Saving the game resets the current Favourite to all 1's

I was trying to figure out why my priorities kept changing. I thought it must be another mod but then I noticed this.

Paused the game
Modified the priorities, got them 100%
Saved the game ( to unload mods etc but....)
Looked at priorities again and any current Favourite aka saved role was now all 1's

Does not affect Favourites not in use.

I suspect this is affected by auto save as well