on my iphone, ipad passcode says wrong but it isn’t.

i am trying to connect my messages from my ipad to my iphone. i tap the on thing and the continue for encrypted messages. the thing is when i put in my iphone passcode it was correct but not my ipad passcode. they had the same passcode, so i changed the iphone and now the ipad passcode, the one i didn’t change, doesn’t work. ik it’s correct. what should i do? what’s going on?? i restarted my phone too.