Hi krickettbug,
When attempting to exit the Guided Access feature, the steps can vary depending on your iPad model. The information in the section "End a Guided Access session" here Use Guided Access on iPad and quoted below can help.
"Do any of the following:
- On an iPad with a Home button: Double-click the Home button, then unlock with Touch ID (if enabled). Or triple-click the Home button, then enter the Guided Access passcode.
- On iPad mini (6th generation) and iPad Air (4th generation and later): Double-click the top button, then unlock with Touch ID (if enabled). Or triple-click the top button, then enter the Guided Access passcode.
- On an iPad with Face ID: Double-click the top button, then unlock with Face ID (if enabled). Or triple-click the top button, then enter the Guided Access passcode."
If the issue continues, test a normal restart Restart your iPad - Apple Support , and if it continues try a forced restart Force restart iPad Force restart iPad - Apple Support of your iPad.
Cheers.