Transfer market bug, 21 years olds

[Lizard]

I bought some riders at the young riders transfer market. I'm afraid I might've hit on a bug here.

Wasn't thinking of the "Only four 21years olds" rule and wanted to buy like 6.. so what came out is that I got 4 riders before the month change and one after it. Don't wanna sell him, don't know if it's necessary or whatever, but of course would if needed.

So, after all I have 5 21year olds, is that supposed to be since one came in the team at Nov 1st?