When you open the panel that shows what stacks are paying maintenance some stacks don't display the name of the region, just a line of dots.
I think it looks like it is happening if you have a unit inside a structure. The two stacks with lines of dots instead of a region name both had units inside a structure, none of the other stacks did and their region names displayed OK.
If you click on these dots you don't get taken to the units.
On the subject of maintenance is it WAD that I am paying 1RP per unit? (Garrisons look like they are free.)