I have the same problem, I wanted to protect the account with a password but I can not find out what password they used for opening the account. Before I can not protect the account I do not risk to pay for a premium account.
Funny is, they just want to help directly if you pay for a premium account, but I do not like to risk that someone knows my password and can get into my Tracker.gg account.
If there is no reaction then I will not pay for this. In my browser it said my password for Tracker.gg would be “undefined”. I tried this to change the password, respond is, the old OR new password is not correct - Great, so it can be I do not fullfill the requirements for the new password or the old password “undefined” is not correct. And yes I also tried it with blank old password, hasnt worked as well.