After many attempts to get my Honeywell T6 Zwave thermostat (https://products.z-wavealliance.org/products/2893) to work correctly, I have finally found a solution. I originally put my thermostat in Celsius Mode since my hub was set to Celsius in the Main Settings. This resulted in the set heating temperature being set to 4.5 degrees Celsius (very cold almost freezing) when coming out of away mode. Coming out of away mode should of set the heating temperature to 22.5 degrees (nice room temperature) as dictated by the scheduler app. Honeywell documentation states that 4.5 degrees Celsius is the lowest temperature the thermostat can be set to.
Setting the thermostat to display Fahrenheit and setting my hub into Fahrenheit and then re doing all my temperature inputs in the app into Fahrenheit has solved the problem. Everything is working as it should.
This definitely seems to be a bug in the Thermostat app that does not allow operation in degrees Celsius. Hopefully this can be fixed so I can go back.