Correct it's PicoStation M2HP. I know is just 32MB of RAM but why it was working fine on version 19.07.5 and now I am getting errors with v19.07.7. Nothing has changed on my end.
I monitor the router's memory, cpu, load, network, connections, etc with collectd + influxdb and grafana I dont see any spike or any indication that I was out of memory.
Filing a bug might be worthwhile if that bug would manifest in routers with 64+ MB RAM.
32 MB RAM devices are abandonware, unsupported.
Possibly 19.07.7 is just that much larger than 19.07.5 that the RAM is not enough. There is a slightly newer kernel with more backported stuff, newer wifi drivers, newer (larger) other packages etc.
If 19.07.5 works for you, just use that.
Alternatively, build a personal 19.07.7 image with stripped features, e.g. without LuCI GUI. That might help you.
I just wanted to let you know that I have installed the newest version 19.07.8 , and everything is working fine so far with no issues for almost a week, with the same settings, packages, etc (everything the same). It looks like there's an issue with 19.07.7 that was getting out of memory.