I have had the same problem recently. I have 2 units (3rd generation)
for a long time. Unfortunately, one of them acts up recently. I'm sick
and tired of it and may change to another brand.
Did you figure it out? I have a similar problem while in the cool mode.
I've reset the unit. I remove all the scheduling and even turn it off.
The unit turns itself back on. The strange thing is my 2nd identical
unit is fine.