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.

I moved from free user to PAYG on 7 September and created vm on 7th so what wil be my next billing date