Doesnt work in low light condition in auto mode - Holosun Military Grade Micro 1x20mm 65 MOA

I rated this product three stars because it doesn't do 1 thing that holosun says it can do. The manual mode works just fine; however, there is a problem with the auto mode. In auto mode the solar panel works just fine when there is ambient light. I actually doesn't even need much ambient light. However, when the ambient light drops the reticle almost completely disappears. It disappears to a point that it is not usable. The manual says that in auto mode under low light conditions the unit will switch to the battery and you can use the + or - to adjust the reticle brightness. I tried to adjust the reticle brightness and it still remained undetectable. I even compared it to my 509T, which i use as a backup sight on my other rifle, and when i cover both solar panels the 509T dims but it is detectable while the 515 is gone. I sent my first 515 back, thinking it might be a faulty unit but had the same problem with the replacement unit. I called holosun and explained the situation and they where completely useless. They said that the unit was behaving the way it should. I told the rep that when the unit is in auto mode that it disappears. He said that i can just push the + or - to adjust the reticle but it still remains largely unusable. I asked why do the 509T and 515 behave differently under low light. Hew said it was because one is a rifle optic while the other was a pistol optic; but, that doesn't make sense to me. When the 509T is under low light situation it switches to the battery and dims a little. The 515 just disappears. If u have the technology for it to switch to the battery and remain visible in low light situation, why not put it on both optics. He said that to just run it in manual mode but that's not the point. I bought it because it have solar and i like the convience of it automatically switching between the 2 power sources. Regardless, i'm keeping the unit and running it in manual mode. If i'm doing a lot of shooting during the day time then i can switch it to solar to save the battery. I just want to be clear that i like the unit and would have given it 5 stars if not for this issue. I would recommend going with the non solar option.