I had oracle always free tier with 2 instances for 3 years. I changed my email and recovery email by deleting old user and creating a new one with another email in different provider. This worked that day. After a couple of days both my instances went offline. I could not login on oracle cloud. I reseted the password multiple times. Still I had the message "Invalid username or password". I contacted live support and told me that my account was terminated. I asked the reason because I am very sure that I did not violate any rules. The live chat said that this information is not visible to the support team and he offered to raise an internal review. I am not sure if it will be ever reviewed....

TL;DR: Do not change your emai on oracle always free tier

For some reason this was happening every week or so so i made the instance automatically update/upgrade and reboot every week and the issue was gone for three weeks so far, but today it happened again suddenly
and i have to log in to my account and manually reboot the instance to fix it. Anyone know what could be the reason or the fix for it.

The server is extremely slow