Similar issue here — can’t get past the solid yellow light.
Tried the solve listed on this thread (without the SD card as I don’t have one)
Opened and set up to connect to app and test functionality — everything worked.
Unplugged and mounted to its location in the room and got stuck on the yellow light. No micro SD card or firmware updated. Just moved, mounted and it’s stuck on the yellow light — device won’t factory reset. 
This camera was a gift so unfortunately, I don’t have the receipt would love if there’s a solve out there.