I was looking for a solution to this for a long time before seeing John's post and figuring it out. Here's a more explicit explanation to hopefully help make this info easier to find.
This was tested and does work on both the Orange Pi 5 16GB, and the Orange Pi Zero 3 4GB. I haven't run into this issue on my x86 nodes as it doesn't appear zram exists on them at all on a fresh install.
If you go to the /etc/default directory, there should be a file called <distro>-ramlog. If you're on armbian it will be armbian-ramlog, for me on Debian it's called orangepi-ramlog.
In this file there will be a line reading
"SIZE=50M"
Simply edit this line to whatever value you'd like, and then reboot the device.
If rebooting the system will cause serious problems, you can use the following command on armbian:
service armbian-zram-config restart
Again, I'm using the official Orange Pi Debian image, so for me, the command would instead be as follows:
service orangepi-zram-config restart
Don't panic if you notice that this command results in the creation of a zram2 and zram3, as these duplicates will automatically remove themselves the next time you reboot the machine