S6 with Lineage OS 14.1 Crashing After Every Call

I used CF-Root initially, then loaded TWRP followed by an install of lineage 14.1 using the instructions on their website.

After making or receiving a call the phone crashes and reboots into a loop of the lineage logo. This can only be gotten out of by pressing HOME, POWER and VOL Down.

I've tried alternative diallers and changing default dialler but all produce the same results.

This is all very frustrating. All I want is a simple clean phone with very few apps and a stable, reliable OS.

The reason I did this was because bloatware on the S6, like Peel remote were starting to throw up unwanted ads and there was no way to uninstall the software.