Screentime Passcode Not Recognized

iPhone 7 running iOS 12.2, screentime, which I use frequently in my attempt to be a caring engaged parent, will not accept my passcode anymore. Before the replies get off on the tangent of "you must have forgotten you passcode" or "someone must of changed it", I can tell you I know my passcode for screentime. I use it frequently. In fact, when this problem first appeared, with screentime not accepting my passcode after the 3rd attempt, I put the phone aside and tried again in a few minutes WITH THE EXACT SAME PASSCODE and it worked. However, after setting my phone aside for about 10 minutes (not enough time elapsed for me to forget my passcode), I tried going back into screentime and it refused to accept the exact same passcode I had just used successfully 10 minutes ago. I'm now in the "wait 60 minute" holding, after which I'm not sure what will happen. Any advice would be helpful.

R