Cannot cancel buy

When I buy two times the same item (mistake) I cannot cancel the last buy immediatly after buying the same item.

There are 2 games where that appened : https://matchhistory.euw.leagueoflegends.com/en/#match-details/EUW1/3685991131/41823712?tab=builds

https://matchhistory.euw.leagueoflegends.com/en/#match-details/EUW1/3682081880/41823712?tab=builds