Many Dish STBs are preset to enter Standby mode after 4 hours of inactivity.
If you modify Flipper so that On/Off only operates the TV, make sure standby is deactovated.
Follow the instructions for your specific STB model by clicking HERE. In general:
Using your Dish Remote, press Menu, then Preferences, then Updates, then DISABLE standby mode.
Some Dish STBs no longer allow you to deactivate standby. In this case, use the Dish timer to periodically change channels overnight and early morning