UPDATE: I went back to iOS 13.7 while it’s still being signed by apple I highly recommend you guys do it. After a few hours I rechecked the battery health and it’s now reading 93% capacity and so far no unexpected crashes or shutdowns. The new features are nice but just are not worth the hassle. Just google “iPhone firmware” and download the right ipsw file. Open iTunes, hold shift while clicking on Restore and select the io13.7 file. once it’s done remember to turn off automatic updates and you’ll be set. hope any of this helps

Same on my XS Max with one added bonus. I checked my battery capacity a few weeks ago then days ago and also made a note of it before I did the update and it was consistently solid at 90% as soon as the update completes I need to take it for a battery replacement at £70 as now it’s worn out. I’m going back to 13 while I can.