Macbook + Macbook pro blanking out periodically while on external monitors

Both my 2017 macbook pro running Ventura 13.7.7 and my thin 2017 macbook also running Ventura 13.7.7 - both - are blanking out temporarily every tens of minutes when connected to external monitors. A sudo dmesg lists:

Failed to read nominal voltage rating key, 

and

Restarting poll type 2. 

It has become more frequent with the latest update. How can solve or at least work around that. Since it is reproduced on two different laptops, it is unlikely to be a hardware issue. It is more likely a software issue, but I am stuck with the latest OS already. I have tried searching on Google + AI, resetting SMC, NVRAM, disabling battery saving, etc, but the problem persists.