... Within the last few weeks I noticed that the master 150 was not consistently resetting in the evening during the resting phase. Any ideas why this has started happening? I am running firmware 1933 (01/08/2015).
It is not exactly clear (to me) just what is, or is not happening, and just what is the effect of that on the Classic.
When the Classic transitions to Float, the Absorb Timer is reset to the Absorb time setting in the Charge menu. In a normal situation, this transition to Float occurs before the Classic Rests.
There is the Auto Reset function, that when is set to ON, begins a new day at 23:59, each day, and "ReBoots" the Classic. Most of us run Classics with ARST = ON.
You might want to check in the Tweaks menu, to see if " ARST " is set to ON.
What is the situation that you are seeing?
Is the Time Of Day Clock set correctly in your regular Classic (not a Classic Lite)?