Guided Access Passcode Screen Freezes

This is for iPad 9th gen with latest iOS which wasn't an option so selected 6th gen. So the problem I'm having is whenever I use guided access, which is a big reason why went with the iPad over a Fire tablet, and I go to unlock the passcode screen or window won't register my touch. It might register maybe 1/20 times if I'm lucky. The current work around I'm using is just a force restart with power and home button, but that is annoying to use every time we need to change something on the screen for my autistic son. The passcode window works everywhere else except for guided access unlock, so I want to know why and if there's a fix??

Thanks.