Hello,
Thanks for the test account! I have found out that Tine produces different responses for different User-Agents.
Without DAVdroid User-Agent:
# curl -vu testuser:XXXXX -X PROPFIND -H "Depth: 1" --data @rq.xml -H "Content-Type: application/xml; charset=UTF-8" https://tine.XXXXXX.tld/tine20/addressbooks/5403d1e2bd563a912415c7ec5adb9a7c2b66a1d5/ <d:multistatus xmlns:d="DAV:" xmlns:s="http://sabredav.org/ns" xmlns:card="urn:ietf:params:xml:ns:carddav" xmlns:cal="urn:ietf:params:xml:ns:caldav" xmlns:cs="http://calendarserver.org/ns/" xmlns:owncloud="http://owncloud.org/ns"><d:response><d:href>/tine20/addressbooks/5403d1e2bd563a912415c7ec5adb9a7c2b66a1d5/</d:href><d:propstat><d:prop><d:current-user-privilege-set><d:privilege xmlns:d="DAV:"><d:write/></d:privilege><d:privilege xmlns:d="DAV:"><d:write-acl/></d:privilege><d:privilege xmlns:d="DAV:"><d:write-properties/></d:privilege><d:privilege xmlns:d="DAV:"><d:write-content/></d:privilege><d:privilege xmlns:d="DAV:"><d:bind/></d:privilege><d:privilege xmlns:d="DAV:"><d:unbind/></d:privilege><d:privilege xmlns:d="DAV:"><d:unlock/></d:privilege><d:privilege xmlns:d="DAV:"><d:read/></d:privilege><d:privilege xmlns:d="DAV:"><d:read-acl/></d:privilege><d:privilege xmlns:d="DAV:"><d:read-current-user-privilege-set/></d:privilege></d:current-user-privilege-set><d:displayname>User, Test</d:displayname><d:resourcetype><d:collection/></d:resourcetype></d:prop><d:status>HTTP/1.1 200 OK</d:status></d:propstat><d:propstat><d:prop><card:addressbook-description/><card:supported-address-data/><cal:calendar-description/><x6:calendar-color xmlns:x6="http://apple.com/ns/ical/"/><cal:supported-calendar-component-set/><cs:source/></d:prop><d:status>HTTP/1.1 404 Not Found</d:status></d:propstat></d:response><d:response><d:href>/tine20/addressbooks/5403d1e2bd563a912415c7ec5adb9a7c2b66a1d5/3a1e3f348ee6698c517161c63e1707856c29a315/</d:href><d:propstat><d:prop><d:current-user-privilege-set><d:privilege xmlns:d="DAV:"><d:unbind/></d:privilege><d:privilege xmlns:d="DAV:"><d:bind/></d:privilege><d:privilege xmlns:d="DAV:"><d:write-content/></d:privilege><d:privilege xmlns:d="DAV:"><d:read/></d:privilege><d:privilege xmlns:d="DAV:"><d:read-acl/></d:privilege><d:privilege xmlns:d="DAV:"><d:read-current-user-privilege-set/></d:privilege></d:current-user-privilege-set><d:displayname>Testadressbuch</d:displayname><card:addressbook-description>Addressbook Testadressbuch</card:addressbook-description><d:resourcetype><d:collection/><card:addressbook/></d:resourcetype></d:prop><d:status>HTTP/1.1 200 OK</d:status></d:propstat><d:propstat><d:prop><card:supported-address-data/><cal:calendar-description/><x6:calendar-color xmlns:x6="http://apple.com/ns/ical/"/><cal:supported-calendar-component-set/><cs:source/></d:prop><d:status>HTTP/1.1 404 Not Found</d:status></d:propstat></d:response><d:response><d:href>/tine20/addressbooks/5403d1e2bd563a912415c7ec5adb9a7c2b66a1d5/6f7c2c2a0e49f390e3a36ba0ebc3338f4b7721da/</d:href><d:propstat><d:prop><d:current-user-privilege-set><d:privilege xmlns:d="DAV:"><d:write-properties/></d:privilege><d:privilege xmlns:d="DAV:"><d:unbind/></d:privilege><d:privilege xmlns:d="DAV:"><d:bind/></d:privilege><d:privilege xmlns:d="DAV:"><d:write-content/></d:privilege><d:privilege xmlns:d="DAV:"><d:read/></d:privilege><d:privilege xmlns:d="DAV:"><d:read-acl/></d:privilege><d:privilege xmlns:d="DAV:"><d:read-current-user-privilege-set/></d:privilege></d:current-user-privilege-set><d:displayname>Test Users persönliches Adressbuch</d:displayname><card:addressbook-description>Addressbook Test Users persönliches Adressbuch</card:addressbook-description><d:resourcetype><d:collection/><card:addressbook/></d:resourcetype></d:prop><d:status>HTTP/1.1 200 OK</d:status></d:propstat><d:propstat><d:prop><card:supported-address-data/><cal:calendar-description/><x6:calendar-color xmlns:x6="http://apple.com/ns/ical/"/><cal:supported-calendar-component-set/><cs:source/></d:prop><d:status>HTTP/1.1 404 Not Found</d:status></d:propstat></d:response></d:multistatus>Note that the response contains /tine20/addressbooks/5403d1e2bd563a912415c7ec5adb9a7c2b66a1d5/3a1e3f348ee6698c517161c63e1707856c29a315/, which is the shared address book.
With fake DAVdroid User-Agent:
# curl -vu testuser:XXXXX -X PROPFIND -H "Depth: 1" --data @rq.xml --user-agent "DAVdroid/0.1" -H "Content-Type: application/xml; charset=UTF-8" https://tine.XXXXXX.tld/tine20/addressbooks/5403d1e2bd563a912415c7ec5adb9a7c2b66a1d5/ <d:multistatus xmlns:d="DAV:" xmlns:s="http://sabredav.org/ns" xmlns:card="urn:ietf:params:xml:ns:carddav" xmlns:cal="urn:ietf:params:xml:ns:caldav" xmlns:cs="http://calendarserver.org/ns/" xmlns:owncloud="http://owncloud.org/ns"><d:response><d:href>/tine20/addressbooks/5403d1e2bd563a912415c7ec5adb9a7c2b66a1d5/</d:href><d:propstat><d:prop><d:current-user-privilege-set><d:privilege xmlns:d="DAV:"><d:write/></d:privilege><d:privilege xmlns:d="DAV:"><d:write-acl/></d:privilege><d:privilege xmlns:d="DAV:"><d:write-properties/></d:privilege><d:privilege xmlns:d="DAV:"><d:write-content/></d:privilege><d:privilege xmlns:d="DAV:"><d:bind/></d:privilege><d:privilege xmlns:d="DAV:"><d:unbind/></d:privilege><d:privilege xmlns:d="DAV:"><d:unlock/></d:privilege><d:privilege xmlns:d="DAV:"><d:read/></d:privilege><d:privilege xmlns:d="DAV:"><d:read-acl/></d:privilege><d:privilege xmlns:d="DAV:"><d:read-current-user-privilege-set/></d:privilege></d:current-user-privilege-set><d:displayname>User, Test</d:displayname><d:resourcetype><d:collection/></d:resourcetype></d:prop><d:status>HTTP/1.1 200 OK</d:status></d:propstat><d:propstat><d:prop><card:addressbook-description/><card:supported-address-data/><cal:calendar-description/><x6:calendar-color xmlns:x6="http://apple.com/ns/ical/"/><cal:supported-calendar-component-set/><cs:source/></d:prop><d:status>HTTP/1.1 404 Not Found</d:status></d:propstat></d:response><d:response><d:href>/tine20/addressbooks/5403d1e2bd563a912415c7ec5adb9a7c2b66a1d5/6f7c2c2a0e49f390e3a36ba0ebc3338f4b7721da/</d:href><d:propstat><d:prop><d:current-user-privilege-set><d:privilege xmlns:d="DAV:"><d:write-properties/></d:privilege><d:privilege xmlns:d="DAV:"><d:unbind/></d:privilege><d:privilege xmlns:d="DAV:"><d:bind/></d:privilege><d:privilege xmlns:d="DAV:"><d:write-content/></d:privilege><d:privilege xmlns:d="DAV:"><d:read/></d:privilege><d:privilege xmlns:d="DAV:"><d:read-acl/></d:privilege><d:privilege xmlns:d="DAV:"><d:read-current-user-privilege-set/></d:privilege></d:current-user-privilege-set><d:displayname>Test Users persönliches Adressbuch</d:displayname><card:addressbook-description>Addressbook Test Users persönliches Adressbuch</card:addressbook-description><d:resourcetype><d:collection/><card:addressbook/></d:resourcetype></d:prop><d:status>HTTP/1.1 200 OK</d:status></d:propstat><d:propstat><d:prop><card:supported-address-data/><cal:calendar-description/><x6:calendar-color xmlns:x6="http://apple.com/ns/ical/"/><cal:supported-calendar-component-set/><cs:source/></d:prop><d:status>HTTP/1.1 404 Not Found</d:status></d:propstat></d:response></d:multistatus>Note that the shared address book is missing!
As a test, I have removed the User-Agent from DAVdroid requests and then the address book is detected:
0_1537872055547_Screenshot_1537872049.png
which synchronizes as expected (only in one direction, maybe the address book is read-only but not marked as read-only)?
Can you report this to Tine and then give us feedback here?