Thanks for the quick answer! I used the official plus edition from your site for flashing. Disabling VoLTE worked. I totally forgot what VoLTE means pronounced... It makes now sense why everybody is asking about it. Sorry for bothering you and keep on the good work. Never had less problems with Pixel Experience than with other roms.
Oh perfect! I said official because sometimes not everyone transitions at the first. And yes, the VoLTE is something very mentioned, mostly because some Indian carriers won't support 3g calls. Taking about the bugs well... I can't take all the credits, most fixes come from sdm6xx team and especially @Jleeblanch (lineage os dev) so huge shout-out to them!