iPhone crashes overnight - SystemMemoryReset log reason "User reclaimable memory dropped below the limit"

When my iPhone is on charge overnight, it almost always reboots daily (or rather, I think Springboard crashes as I am not prompted for Face ID).

My iPhone 13 is currently running iOS 16.2 and for at least the last few months, when plugged into power, it has crashed sometime between 1am and 2.30am. I know this because when I wake up I have a notification asking me to unlock to re-enable Shortcuts, and also it disengages Do Not Disturb (and so I often get woken by it buzzing from notifications).

One day I went to Settings > Privacy & Security > Analytics & Improvements > Analytics Data, and noticed there was a SystemMemoryReset log file with the same date and time as the overnight crash. The 'eventReason' in the log file is always:

"User reclaimable memory dropped below the limit. User reclaimable current: 59%. User reclaimable minimum: 62%"

In the latest example, it appears to be caused by 'com.apple.WebKit.WebContent' ('largestProcess') but this isn't always the case - I've seen other examples of 'largestProcess' but they never seem to be 3rd-party apps.

I have noticed other users have also experienced this but there are no explanations or useful fixes. I really do not want to have to reset my phone.

Does anyone else have this issue?