Technically clover is not compatible with Tractor Swathing, you must be using Swathing+ as well. What map are you seeing this on so I can confirm the growth states. It seems like a lot of the maps with alfalfa and clover have different growth states set-ups.
Judith is one of a handful of maps I have now that I check things but I must have not checked that one when i first made Swathing+. Can confirm, Judith clover is harvest ready at state 4 where my mod is set to look for state 5. Easy fix but I am also looking into another issue and don't want to push another hotfix until I sort that one out.
If you wanna fix it on your end, I could walk you through it pretty easily if you shoot me a message on Discord (username Bbdude)