I encountered this problem in previous versions but it still exists in davdroid 0.8.0. I sync with mailbox.org and even multiple phone numbers are no issue for me - they are getting synchronised as they should. My problem is, that sometimes (over night / after a new sync) two contacts get merged into one. For better understanding:
- Entry: Person A, mobile a, mail a,
- Entry: Person B, mobile b, phone b.
On my phone (after sync):
- Entry: Person A, mobile a, mobile b, mail a, mail b
Which accounts are affected seems random to me. On the mailbox.org server, there are still Person A and Person B separately and unaffected. Several new setups of my account in davdroid only lead to a short-term solution.