[OpenBeken] Silvergear CB2S smart plug - suddenly behaves faulty. Maybe test flash? How?

Are there any tests for a faulty or strangely behaving OpenBeken-flashed device?

Got a 'smart plug', a Silvergear. I hacked it a few years ago and programmed it with OpenBeken. It monitors my shower heater (boiler), and it also works like a timer for the heater, so it only heats up during daylight hours (got solar panels).

Just the other day, it suddenly stopped - Cold shower, brrrrr.

I tried to reset it. Managed to burn OTA to the latest software, 1.18.300. That took a few tries before it finally connected.

Then I set all the config parameters as they were before.
However, it is still behaving erratically. It randomly switches off and on again. It is not trustworthy at the moment.

Maybe the flash is faulty? Can I test that somehow? Where can I monitor the flash free space/occupied space? Can I do a full reset of the flash without corrupting the OpenBeken software, of course?

Or do I just replace the brains? It's a CB2S module. I do have a TYLC5 module; can I use that?

Your input is appreciated.
AI: What exact Silvergear smart plug model is it, and what is the boiler/heater load in watts/amps? Also: does the plug or relay/power supply get warm/hot when the boiler is running?
Exact model number is missing.
The heater draws about 700 W.
The relay is heating up somewhat, but not alarmingly hot.
AI: Can you post the OpenBeken console/log output around the moment it switches off/on, plus your current pin config, autoexec/startup commands, timers/rules, and whether MQTT/Home Assistant or another controller can still send commands to it?
Since it randomly switches off and on, I do not have logs. It may occur only once/2 hours.
It does seem to report to my Home Assistant server.

A known problem for cheap plugs.
Capacitor gone bad. You'll have to replace it.
https://www.elektroda.com/rtvforum/topic3898805.html

Were you running it with power save enabled?

>>21958087 Ok, I'll try and open it up. Did it before and just used easy glue (not superglue) to close it then. I do recall this solution (replace capacitor) from earlier faults I got. I might have replaced it already, but I did not record it.

Not sure I used Powersave, I do recall having issues before and then invoked power save, but since I reset it all I do not know the exact .bat files I used before. It is not in the .bat files currently, so probably not.

Can you explain in technical detail what powersave does exactly?
Thanks.

Powersave command does exactly what its name suggests - it enables the chip's and internal wifi modem's power saving features, significantly reducing the module's power draw. Reportedly - reduces the capacitor load, prolonging it's life.