Both 0.8.1 and 0.8.0 versions affected. I sync to ownCloud server (v8.1, yesterday upgraded from v8.0) installed on my computer. OwnCloud correctly displays 469 contacts, DAVdroid synchronizes them all (I monitor number of contacts during synchronization), but as soon as it finishes, number of contacts comes down to 37. I tried several times, contacts are always the same. I even uninstalled Viber and WhatsApp, thinking they could mess with contacts. One thing that I noticed, is that vCard version (DAVdroid settings) is 4.0, I’m not sure what was it before upgrade to 0.8.1. On my 4.4.4 rom the vCard version was always 3.0.
Currently I’m running Lollipop (Euphoria OS). Logcat extracted, I can upload if required.