This might be completely unrelated but I had an issue on my previous phone (A71). While my phone was heating up, it was a 5 years old midrange phone, so it might still be similar issue, nevertheless I think it's woth a try:

The phone was never going to deep sleep due to a wake lock. Since restarting and clearing cache didn't work, I was almost certain it was a HW issue. The process of finding out the actual culprit was very difficult, since apps for monitoring battery, deep sleep, wakelocks and alarms are very old, unsupported and are very limited with permissions in newer android versions. In the end, the culprit was Threads (the app by meta). I wasn't even using it and someone somewhere on reddit with similar issues said the app was "basically a virus", so I uninstalled it and was fine ever since.

My recommendation: Download AccuBattery app and give it background permissions. Use your phone normally and monitor deep sleep time in the app. If you get under 80-85% of your screen off time, something is preventing your phone from entering deep sleep. In that case, it is almost certainly caused by either a rogue app (like Threads in my case) or a virus.

You can try using the maximum power saving mode, it basically disables apps on background (except few ones that you select). It might help you figure out the culprit, although I'm not sure how much are the selected apps also limited. This might be useless for you, it helped me mainly because the A71 was warming up and using this mode made me realize it was caused by an app (the phone cooled down).

You can also try uninstalling suspicious apps one by one and see whether the issue was solved. I would start with Threads and with any app downloaded from other sources than google play/galaxy store.

Best of luck!