Did this occur when you planted them quickly all at once? Or did it still work if you take your time between each plant?

Thats because the way and area where plants spawned was changed like 3ish months ago.
Plants now spawn randomly at certain origin levels around the player but equal to or above feet level.

So when you plant if the ceiling is too low compared to the spawn threshold the plant can be spawned and clip into the ceiling which makes it go into the apartment above. (Same premiere as when it spawns outside the map due to being too close to a wall that boarders the map).

Solution - Crouch when planting, if the roof is just so low that it's spawning into it regardless then you need to plant somewhere else and gravity gun the plants into your apartment after placing.

It's dependent on the map though, like FMC only had VIP Apartments and one other building that could spawn it into the roof without standing on something and VIP Apartments was fixed by crouching.

It was changed this way so people would stop spawning them out into the void of the world.

Maybe a couple of origin can be changed for height without messing anything up.

yaya u all can stop complaining i fixed it, tho im sure u all will find something wrong with the new system to complain about anyway

I Basically live in Noisyworms house to get them.

NIGDASHTGUIDSHFJUKLDSHGUIDSHNDSIKGLGHDSUILKTFGHDUKLHBNGXCKHTIUDLSTG syle didnt upload shit yet u fuckin jew cunts

Planting has seemed to be fine for me now.