I can confirm that mherzberg’s apk fixes this for me. Thank you!
Previously, I was getting error messages in the notification menu every hour or so. Unfortunately, I forget what they said precisely.
I attempted uninstalling DAVdroid, then installing version 0.7.7. My phone would only import three contacts (out of 150). Oddly enough, I think these were the only contacts that I had added via the phone/DAVdroid. The others had been added/imported via OwnCloud’s web interface a while ago.
I also attempted installing DAVdroid 0.8.0 and 0.8.1. Neither fixed this issue. Only when installing mherzberg fix did it work. Thanks again!