Issue with dot getting lost outdoors - Leapers UTG Red 4 MOA Micro Dot Reflex Sight w/Adaptive Base

I purchased this Micro Reflex Sight for my 10.5 AR Pistol build. It fit nicely and very light weight even with the UTG riser.
When I got it, I thought the dot was a little dim, even at its highest setting. I changed the battery and no progress. I took it to an indoor range and it worked ok. But when I brought it to an outdoor range, I couldn't see the dot.
I contacted Leapers/UTG and they had me send it in to check it out. They determined there was a problem and sent me a new one. The second one works better now even outdoors. Significantly brighter. It does what I need it to do. Great customer service from UTG.