Is there anything in your SourceMod error logs regarding failing to parse tickets?
EDIT: TF2 is still using ISteamGameServer012, so there shouldn't be any problems here.
Best thing you can do is set steamtools_dump_tickets to 1 and send me the file it writes when you join the server.
That said, for you the [F2P] tag is at the end of your name unlike everyone else... so make sure it's actually this code detecting you.
I wont be happy if I spend time investigating this and everything is fine
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