"They (Ameritrade) also said that a recharacterization from a Traditional IRA to a ROTH is just called a Roth Conversion but said they are otherwise the same thing."
What the person at Ameritrade told you is nonsense. That person was inadequately trained. A recharacterization and a Roth conversion are entirely different transactions.
"the ROTH Conversion form I filled in asked what tax year, and I filled 2021"
That would make sense for a recharacterization but not for a Roth conversion. Hopefully Ameritrade did not process a recharacterization instead of a Roth conversion. You need to check that. The only recharacterization that should have been done is the recharacterization from Roth to traditional. A second recharacterization, back to Roth, would be an impermissible revocation of the first recharacterization.
