It does show up as work time in some places as it pretends to be work time to the base-game to not mess with to much other stuff, so that can be normal with that helper-mod you have to select it. (I cold take a look if it is possible to inject the real name in there)

If you don't have the school-area disabled in the mod-options and set up a school area it is currently the only way to see if they get assigned to school-time when the area is highlighted in yellow and they move to it. (The school area stuff can be messed with by other mods, but as far as I know it is only that they don't get out of it anymore not that they never get assigned to it)

It may take a couple of seconds of running ingame time to switch sometimes, as it is cached to prevent performance issues. Otherwise I am not really sure. (I plan to rework the school-part at some point and have more of a classroom setting and schedule which may make all of this easier.)

Ah, the helper mod in question is RimHUD, it can be toggled on and off at any time (unfortunately I forgot to do so when I recorded the issue). The Work issue still happens via toggling it off or without that mod active, though. Even without any other mods at all (save for the dependences) as I mentioned before.

The issue still persists, but alas, I'll ignore the school section of the mod for now. Best of luck with that rework!