"Maximum of 2 at any position"

My fantasy team is as follows:

• Huni (Top) ~
• Kikis (Jung) ~
• PowerOfEvil (Mid) ~
• Sneaky (ADC)
• nRated (Supp) ~
• Pobelter (Flex Mid)
• SK Gaming (Team) ~ [~ = EU so currently locked in]

As of yet, my 2 NA players are still able to be swapped out. I tried to swap out Pobelter for Apollo, but when I did this error message came up:

The exchange would cause your team to violate the position cap for the league, which is a maximum of 2 at any position.

Pobelter is a Mid and Apollo is an ADC, so if I were to swap them I would have 1 Mid and 2 ADCs. As far as I am aware, this doesn't violate the above error. I'm not sure if this is an error on thee client's behalf, or misjudgement on mine so I would appreciate any insight into this issue.

Many Thanks,

Nebida (EUW)