Screen time/downtime not working

i have downtime set up on my daughters phone from 930p-7am. I also have specific app limits set up. The downtime part seems to randomly stop working. No she is not over riding it. I then reset and it works for a few days then stops again. I noticed tonight that it was working for all apps except TikTok. Yes I have powered off and on, current update is installed, you can see from her Home Screen that the hourglass is not beside the TikTok icon like all the others. I have tried uninstalling and installing again and it still does this. This is a huge problem. It allowed her to be on TikTok for hours today.