Problem with sync between android and web app

[TiCaillou]

0_1490702551664_debug.txt
0_1490702652294_davdroid-8851-20170324-090352.txt
I installed nextcloud 11.0.2 on a mutualized hosting ovh. The cloud works correctly. I have a problem with the synchronization between my android smartphone and the Web application.
I installed davdroid from f-droid and I configured the .htaccess with rerouting .well-known. I obtain my address books and my schedules but no synchronization. You can help me please.
Thank you

[rfc2822]

503 Service not available seems to be a server problem. Did you ask Nextcloud support?

[TiCaillou]

But synchronisation work between thunderbird (lightning) and (two direction) web application.

[rfc2822]

@TiCaillou Then it seems like the server error only appears in responses to DAVdroid requests. Did you ask Nextcloud support?

[TiCaillou]

It working with caldav sync adapter but i have not addressbook.