Here's my guess. You have the drawing set to Ft-In but not forcing a roundoff. (This is the way I set mine, although I would prefer decimal all the time, but fractions are the "std" here.) The dims that show as " dims are exactly that. The ones that show the decimal are not exactly that (may be 25.0001), or the dim does not match a fractional value of the denominator that you have set, such as 16 or 32. The reason I like it that way is because when I place the dims on the drawing, I am alerted to the ones that are not designed to a fractional value, and then I have the opportunity to decide what to do with them. I may go back to the geometry and change things such that they are an even fractional value, I may decide that forcing them to round off to a 32nd is fine, or I may leave them a decimal because that's what I really want. Whatever the outcome, I get dims set to fractions for the shop where it doesn't matter, and I keep the decimal ones where it does matter.
I ended up using the Overide to force these to fractional and to round to a specific denominator. Then they show up looking correct.
I was hoping there was a way that didn't involve using the Dim Overide. But the way you describe using this "feature" to check design intent does have its benefits.