Strange issue. I installed this last evening. I have an Apple Smart Case for my iPhone XS Max, which always charges the phone first then the case. I use a magnetic charger, which has been working perfectly. This morning after an overnight 9 hour charging, the case was fully charged again but the phone was only 60% charged, and the phone was charging from the case. Never seen that before. Both are always 100% charged in the morning. Note the different battery levels while on the charger overnight from May 20 and May 21.
I removed the Apple Case, rebooted the phone, checked the battery health (100 %), and put the phone back in the case again. After 7 hours, the case charge is now depleted and the phone is at about 90% charged, as is usual for me for this time of day.
I don’t know if this has anything to do with this beta, or not.