I installed the multiple followers mod and since that every time I go into sneak, the followers leave me... I have to run back to them and talk to them for them to follow me again!
I removed the mod and the same behaviour still happens.
LL
That mod seems to have a large number of loose scripts that are placed in your Data\Scripts folder.
When you removed the mod, did you delete those files? If you didn't, some of them will definitely continue to be functional, as they overwrite vanilla scripts. (Scripts like that should really be packed inside a .bsa archive by the mod creator, so that they are deactivated when you disable the mod.)
And did you continue playing from a save created before installing the mod? Sometimes some mod data, like references to scripts get stored in your save, and continue to have an effect there. (The first question may actually be more critical than this one.)