Home made yeast cinnamon rolls deflating? I use an old time recipe that uses high-gluten flour, mashed potatoes flakes, sugar, salt, oil, yeast, eggs - I make them very often and lots of times have no issues.  However, lately I'm having issues with them falling after I get them out of the oven.  They come out looking wonderful, but as they sit they fall flat.  Any idea of what is happening?

More details:

I proof the yeast each time to be sure it's alive. I use active dry with 3 tbsp yeast + 1 tsp sugar in 105-115 degree water to proof it. I could have gotten sloppy as mentioned, being in a rush to get them done might have made me try to hurry things a bit too quickly. I will also try putting half the batch back in for 10 additional minutes to see if that cures the problem along with working the dough just a bit longer.
Next time pop half of the batch back in the oven for an extra 10min and see if they too fall.
Getting the gluten to really set may be all that is needed. 

If not, dough might be a bit weak -shorter strands of gluten with a lot of starch- and decreasing water or working the dough longer are the next possible experiments.