Lost data after switched off power

I’m running OH on Raspberry. Last time I had problem with electricity and my UPS didn’t manage to power RPI for long enough (UPS is also feeding NVR).
What I observerd (not firtst time) is I’m loosing data from few months. This problem doesn’t exists when I shutdown or reboot OH.
Should I make additional changes in persistence? For now I don’t have any personilized setting for persistence

From my point of view this issue is less related to Openhab, more to the stability of underlying operating system+hardware.
More backups, also online backups of your database, could help in future.

That should be related to zram.
If power is lost zram will not write back to the hard disk.