Yep, defo happened to me yesterday and I was very surprised because it'd been fine for a looooong time and I was doing the 100 baby challenge so you can imagine the amount of times I took my sim to the hospital!
So what changed? I went back to my old save after completing the challenge, pretty excited not to play with babies for a while! I also obviously reintroduced my mods folder and made sure ALL my mods were up to date and compatible and all that.
After a while I actually started missing playing with tods (how you just forget the struggle ahah !!) so I got my sim pregnant and took her to the hospital when it was time. First off, the only worker on lot was a ghost assistant... can we do something about that too while we're at it? I actually hate how npc and townie ghosts just carry on with their lives as if they never died!! Just random ghosts everywhere as bartenders and nurses and whatnot... Come on! Anyway, I'm digressing... So, no employee on lot at first except the ghost at the desk, then some nurse showed up by the sidewalk and stayed there whole time, not even pretending to do something like when you play the active doctor career you know (doing tests, checking in patients, ANYTHING).
So, usually my sim shows up and is checked in within a few minutes, taken to the labour table and that's that, I don't need to do anything, not even check her in manually... But not this time around, so I tried to check her in myself... Nothing happens, and no doctor on lot to help her give birth either. I don't know what the problem is, I'm wondering if it could be related to spawning doctors? It would make sense that she can't give birth if there's no one on lot to help her out...
So i've been looking at some of the comments and I don't know whether the table is in the original colour or what. I'm using Plumbella's wonderful save as she renovated every lot. The hospital is defo renovated, I don't know about the tables and their colours though honestly.. But it does feel important to point out that I was also playing with a renovated save for my 100 baby challenge, but a different save (I'm not too sure I started the challenge a long time ago but I think lilsimsie), and possibly with the hospital lot unchanged.