HD Interactive Set Top Box switches off Power every night.

Yes, I checked the STB info,

It's the latest firmware:

Firmware version: OTV514_SHBNFX_HDI_BLD9.67l_190411_0

UI version: 2.3.57r5

Just to add on, I can turn it off to "red standby mode" in between through the day. But if leave it for many hours, for example, the next day. It will turn off completely with only the network amber light remaining. Once that happens, neither the remote or physical button on set can power it on. Only way is to reboot manually by turning off main power.

In this case, we need to refer you to our Customer Support via Facebook Messenger by clicking the link below as this will require further technical assistance. Thank you. 

Update:
The TV set box now constantly switches off halfway while watching. Same issue, with only amber yellow light on, no power. Tried rebooting like before, it will boot up and works for 5 mins before switching off again. It looks like the unit is faulty. What should I do? Should I get it replaced?

We have to determine first if the set-top box is indeed faulty. I highly suggest that your reach out to our Customer Support first as they will give you the proper assistance regarding your concern. Thank you.