Not sure how i missed that it was a JV3 not a JV33.
if you are using a bulk ink system this could be some of the problem.
I say this as I had a JV3 that was bulk inked and my cyan would always bleed into the yellow if I did a nozzle soak. if I did it over night sometimes it would bleed all 3 heads (6 color machine) I believe that most of the problem came from the bulk ink system being a little low in height which did not create the proper pressure on the dampners. If I pulled ink with a syrienge when you removed the syrienge the dampner would stay closed for a while which means there is a vacuum and thus when soaking I believe it would suck up some cyan.
I replaced caps, dampners, heads, and pumps on that machine (not for this reason) and it never did stop only thing I think it could have been was the bulk ink system.
Have a JV33 now and love it.