D-Series couplers not working, can't find the culprit

I noticed that I could not couple any trailers to the D-series, and when using the quick wheel the option for the couplers says it isn't available. This issue has only affected the D-series but has affected all configs and all hitches, ball, pintle, gooseneck, the lot. I presume there is an outdated mod causing it but I can't find any hint in the console as to what could be causing it. I have tried deactivating mods that would be likely to cause the issue but no dice, cleaned cache, all that. any advice would be appreciated.

 

It works in safe mode (which I did try before posting, just forgot to mention in the OP), so it has to be a mod issue, I just wouldn't know where to begin looking. I disabled all the mods I could think of that affect the D series, and no luck. So I suppose the next step is one-by-one enabling of mods to find the culprit, as time consuming and annoying as that may be. I was hoping that someone may have had a similar issue and would know which mod it was.

EDIT: I deleted a few (5-6) mods I felt were unnecessary, and it seems to have fixed it. However I don't remember which exact mods they were.