@jimmy Thanks for the update and good to hear that it now works for you! Maybe the thread can help others with the same problem.
DAVdroid > 184.108.40.206-ose compatibility issue
On Android 4.0.3, the last working version of DAVdroid is 220.127.116.11-ose. I’ve tried 1.6.2-ose and 1.6.3-ose and both make android freeze when trying to sync.
v18.104.22.168 is doing the job anyway, thanks for your work.
See DAVdroid 1.6.3 release notes: Android 4.1 is required now