Alakazam Bug in Re-learning Old Moves

Trying to re-learn Psybeam in Goldenrod City via the Move Buffet NPC on my Alakazam. After trying to swap out old moves for the Psybeam my money would be deducted but the wrong move would be replaced on my Pokemon's moveset. For example if I try to switch a move with Psybeam, it would instead be replaced with another move e.g Disable/Miracle Eye/Teleport/Reflect. Sometimes the moveset positions would also be changed, so that the move I tried to replace did not actually disappear but another move does. This has messed up my Pokemon's moveset and cost me many thousands of Pokedollars as I've attempted it many times, so it's definitely not me clicking the wrong move to replace.

Additionally, there is a problem with move learning which the move-relearning stemmed from. Whilst learning a move through levelling up, most recent case Psycho Cut, I try to replace a move already on the moveset (Miracle Eye), but after leaving battle the move is not replaced. I then learn Recover through levelling, try to replace Miracle Eye with this once again, but instead this time Miracle Eye is replaced with Psycho Cut... This is becoming increasing annoying.