If this bug was accidentaly made by the new copper membership fee, then I suggest if you really want it badly, then pay for it again

Do you have any reference for it? It looks like this is not a isolated case. People have posted at least 2 more accounts with the same issues.
Really want to know what happened

The fact that both accounts was registered last year and hasn't been also a deranked Full Member, instead theyboth availed the Copper Membership. This maybe a bug or certainly they possibly achieved to bypass the limitations upon their accounts.
The said account are still active, might want to ask them on how they did achieve such thing.
As for @Hakorede mentioned that they're not a new registered Copper Members then we can say that this might be a bypass. I may sound contradicting myself here but because if it just a bug, then why is it only a number of them and not the others who availed it back then?
I remember there was a time in 2018<>...
Would you mind getting us on that matter? You can provide us a link or just a clue where you've found it recently.