Controller bug in rivals

This is one of the most annoying things that happens because its unfixable

im not sure what triggers it or causes it but randomly when i enter a game of rivals (im on pc using a controller) it switched my input mode to keyboard and mouse instead of controller and doesn't give me a choice to change it

i can use my controller in the menus but in game its unusable  and im forced to either use a keyboard that im sure no one uses or even knows the controls of or i leave the game and take the loss which so far has costed me a new divison and a 10-5 in champs