It’s unclear what you did to your system. Did you reinstall the openhab package only ? Or the OS ?
Syncing ZRAM no longer requires to restart OH so openHABian no longer does this in quite some time. As it obviously does on your system I believe you’re still running an ancient OS setup.
It’s /etc/systemd/system/zsync.service usually calling /usr/local/sbin/zram-config.
You can replace the latter with the latest version from https://github.com/ecdye/zram-config.
Well or you can install everything from scratch on SSD as recommended by some lonely shouters here. But then you will no longer receive help from myself or others on this forum as it’s no longer a supported openHABian setup so if you do and when you’re in need for help then for support please turn to those that recommended doing so.