I just got one yesterday and installed DMD2 on it. The maps and GPS work fine, I have not had chance to test anything else yet. For the price it looks like a good unit, time will tell on how well it holds up on the bike
Could you try it outside, with direct sunlight or in very bright environment?
In my country it’s raining, but one thing that I like the feedback it’s the brightness outside, 400 nits seems a bit low.