Tags not staying checked

We are using the Gravity Forms Infusionsoft Add-On plugin and are having a hard time with the tag selector. It seems that the tags become unselected, but not always. I’ll set the tag and go set the tags in a few other feeds. When I return to look at the ones I’ve set, more often than not, the tags we chose are no longer checked.

Any ideas as to what may be causing this?

We increased max_input_vars to 3000 and memory to 512M, so there shouldn’t be any issues there.

@zack, I emailed this question to you, obviously better to reply here so it might benefit others.