iphone mirroring won't toggle languages

I don't know if it's because I had to factory reset my iphone, or if it's some issue with the Mac OS/app now, but when I went to use the mirror function, it won't let me change the language on the phone anymore. Neither the caps lock key nor the FN button will change the language on the phone. Of course the cntrl + Space still only affects the mac.

Is there a way to fix this? I don't use the actual computer too often, so it's been a week since I last used this function and it was working fine. Did something update over the week causing some weird bug? I didn't try it before resetting the phone, so I don't know if the problem is because of the reset.

I did test this with different keyboards, neither worked. I checked using one of them with the iphone directly, no mirror, and it works fine. So it's just when in mirror mode.