So, you have the Herpstat and probe set on the outside of the tub between the UTH and the tub? And then you are getting a reading of 93 from the Herpstat? And then this 95 is coming from a temp gun on the inside of the tub on the floor? At the exact same spot as where the Herpstat probe is? I mean once you have that changed and let it sit a couple mins until it stabilizes. Then temp gun the probe from inside the tub and see if the probe temps matches the Herpstat reading.
I mean your temp gun could be off a couple degrees too and when you temp gun anything, you want to do it within an inch or less as the air can change the temp as well on the gun.