Little Update from my side. Had the probably same issue today on a OrangePi PC. SSH wasn't working any more, Ping worked. After Hard Reset everything fine again. This Board is at another Geo Location with different Power Supply. I have now installed the logging Cronjob + Telnet to check if it is really this issue if it happens again.. (This Board had 5.4.20-sunxi #20.02.1 installed, will update now)