Hi.
Thank you for your reply.
I did not change it, and I can still log-in in phpMyAdmin with the "MySQL root Pasword" that the CWP installer gave back in February, when I installed CWP on the VPS.
What I did change related to MySQL is that I used the CWP upgrade script to 5.5 months ago (but I think that was way before the issue occurred, the issue started exactly on the day where it upgraded to 0.9.8.15 (it's the last email that says 0.9.8.14, but the typical no update something line is missing, meaning it updated exactly on that day as it usually does)) and also I lately upgraded manually to 5.6, which was a bit complicated, but the issue is still the same.
I'd be interested if other users have a similar problem (maybe they don't read the log that closely) or if it's only me.
With kind regards