Check the properties of the tile you built it on - if it's bad for farming, even fully leveled up it'll round down to 0. I haven't seen it with farms but it happens with crystal mines when on bad mine tiles, who also have a low items-per-tick amount. I'd have to check the code in dnspy but suspect that the malus gets applied to the amount per tick first, then it's rounded to int, then the plus is applied and rounded again - so if the malus brings the base number to 0, 0*n=0
Otherwise, it might just be slow. I was a bit confused at how long it was taking the first time because i didn't notice the tick was longer than gold
