I have two servers (live and dev) and when I switch between the two, I can see available users on one but not the other, I have to manually search instead and can then select them. It's frustrating. When I also create user filters, I can't see any of my groups, I again have to search for them and then they're available but I can't open a drop down to see who is in each one. Please see below the difference between the two. It's like I haven't enabled something somewhere. I've never seen the options appear like this.
Live is left, dev is right. Lists blanked out. Any advice would be greatly appreciated.
It looks like there may be a lot more groups on the Live server (it mentions 123 groups in the screenshot). Once you get above a certain number of groups they are not all displayed in a list, for performance reasons. How many groups do you have on the Dev server?