I had the same problem with /var/log filling up.  It was causing Jellyfin playback to fail.  I tried disabling armbian-zram-config service in the config file, but then the /var/log got mounted to an armbian-ramlog device that is the same 50M size.  So I ended up changing the armbian-ramlog size to 500M in it's config file and re-enabling the armbian-zram-config service in it's config file.  Now it's once again mounted to /dev/zram1, but it's now 500M.