Help me debug my System. HA becomes unavailable randomly every ~10 days

So, I have a Dell OptiPlex 3050 running HA OS, and have this problem for months. Updates are always done, memory, cpu, temperature are always fine, and logs give no apparent reason to explain my problem.

This last time, for example, the last time my cpu sensor updated was on the 18/01 at 10:00:57 and my last home-assistant.log.1 is this: 2023-01-18 09:29:56.647 ERROR (MainThread) [homeassistant.components.tplink.coordinator] Error fetching 192.168.15.81 data: Unable to connect to the device: 192.168.15.81:

something really general, 30 minutes before the HA apparently went offline.

I also created an automation to log in a file if my HA ip stopped getting successful pings (it worked when the network went down, but did not logged anything this time).

Please help me introduce some procedures to better understand my problem.