Low dynamic hot water pressure throughout the house
There is a restriction, somewhere. You could use your gauge to verify that the pressure (while you are flowing from faucets) at the water heater is good (you've only done so qualitatively so far, and you have means to test it quantitatively, so....) But basically somewhere in the line is something that is restricting  water flow - perhaps a clogged or under-sized tempering valve (if there is a tempering valve) or the one I keep mentioning because it was a bear to track down and semi-unbeliveable when I did, an elbow almost completely plugged with solder. Could also be pipes plugged with mineral deposits.

If you open the hot faucets and pressure at the water heater stays good, move the pressure test up the line - somewhere it will get worse, and between there and the last place it was good is the problem.

Incidentally, 95 PSI is on the high side for many fixtures - you might want to add (or adjust if there is one) a pressure reducing valve and get to down to 75-80 PSI MAX.