[HELP] Instance goes unresponsive after a few minutes...

I am trying to RESTART using AWS after several years, I have created a new VPC and Instance per the instructions and I can start it, ping it and ssh into it (it's Red Hat Linux - Free tier eligible version). The problem is that after about five minutes it just stops responding to network traffic, the ping and ssl session die. Oddly enough the instance still appears to be running and I can get a screen shot showing the console looking okay.

I read somewhere that this is a known issue with "reactivated or old AWS accounts" and can only be resolved with help from Amazon. Could someone please take a look??

Instance: i-0b0c25b5126971d83 (RHL 05072019 1)
Network Interface: eni-00ef3fe3eb30ef3b4
Public IP: 3.210.51.27
Status Running but unresponsive

Thanks, Dan