Hi there, did you resolve this issue, as I'm experiencing it just now. Thanks
No mate never got it sorted.
So I was running into this low volume thing and it was driving me nuts. Did a factory reset a couple of times, kept changing settings on my receiver and TV, pulled out my hair, just nothing seemed to work. After going through the chain of my devices and turning off CEC and any control through HDMI settings, I somehow rediscovered that there's a volume level for the Formuler box itself. Normally when I adjust my volume using the GTV-BT1 Bluetooth remote, it only adjusts the volume on the receiver. Two days ago I adjusted the volume on my remote and saw that it wasn't using Bluetooth, but using the IR signal (there's an indicator on the remote that flashes red when using IR, and blue when using Bluetooth). I then saw an unfamiliar volume indicator, which I saw one other time when I first started setting up the device months ago and completely forgot about. It was the volume level for the Android OS on the Formuler, which was at 50%. After turning that volume up to 100% it completely fixed the problem. Now I don't have to crank my receiver up to 60+ just to make out dialogue, only to forget it's up that high and get a nice jump scare when I play something else before I remember to turn it down.
TL;DR: I'm not exactly sure how I did it (didn't feel like doing something that would break it again after FINALLY getting it fixed), but I imagine the best way to fix this is to make sure any external volume controls are disabled, and try adjusting the volume on the Formuler remote until you see the Android OS volume indicator, then crank it up to 100.