It happens on all miners with the 5700 and old HiveOS version...
Install HiveOS with Kernel 5.4.0-hiveos #108, as I see you have a very old Driver AMD 20.20 the most stable is 20.40 that hasn't go a memory bug lead with the 5700xt.
If you take the last image realase of update inside HiveOS you will avoid that Free Ram that you have :-)
It was solved on this realease:
0.6-190linux
2021-01-08
LINUX SYSTEM IMAGE
New Stable branch
Hive Linux client: v0.6-190@201106
Universal boot mode: BIOS | UEFI
Linux kernel: v5.4.80-hiveos
Drivers version: AMD v20.40, Nvidia: v455.45.01
Universal image with "support from the box" AMD Polaris/Vega/Navi and Nvidia 10xx/16xx/20xx/30xx
Its not possible, i was using TRM for at least 3-4 months and after that 1 month PM without any memory problems. It started when i changed to lolMiner.
And if i change back to TRM, there is no problem with memory. It shows 6.6gb free ram all the time. (And if you havent noticed its RAM not VRAM)
(5.8gb now :-) )
But i can try to update that driver when i visit the mining site. Last time i tried 20.4, it didnt work, cant remember which card didn't show up.
and thanks for advice.