When picking a date and time for reminders, you can tap on the time to bring up a keypad to enter the time directly (added in iOS 15). Currently the picker is blocked by the keypad that pops up when you attempt that, feature still works just an UI issue.
Here’s a gif showing the issue:
(Notice that the reminder time is correctly set to 3pm)
Oh geez I had no idea. Thank you for reporting! Will have to see if there’s a simple fix, though I totally had not accounted for this with our panel design