Used it with only one site for a year now, worked.
Added two more, made an account.
Saw that the account (free tier) can be run only every 6 hours. that's pretty bad and useless.
Decided to close the account because its unnecessary.

What happend is that all my watchlist was completely empty because they sync online and offline.

So don't use an account or never delete one.
I could start over, but is tells me now "Used 0 of 0 available monitors" wth

I'll make a python script, thanks for nothing