I have both the SY and the SH. My SY has been having some POI issues as of late, causing me to have to shoot before every hunt. POI all over the place, recitals disappearing, but not the stained-glass issue in a while. Maybe only 3 times in over a year. I use the Apex external power source and do not install the batteries. Powering the unit down is basically unplugging the battery. I never, NEVER, take my SY off of my AR. I just use the SH as a handheld. I have called and emailed BO with no response. I have read through countless forums and only see that maybe moving the QR mount forward or something to help keep zero? But that doesn't explain the recitals disappearing and having to do the old hold 2 buttons and hit the center button 4-time trick. If I need to send it back I will, but man this is a terrible time to be with out.
If you do not power the unit down through the scope, settings will not save. As part of the powering down procedure is when settings are saved including reticles, colors, and backgrounds. I am a bit worried if you are powering it down via external battery this may be causing some of your issues. The only Bering products where you had to power the unit off by disconnecting was the original Hogster (pre-Vibe models). Even for those scopes, you had to go through the power-down procedure, the settings would save, and then disconnect from power.
If I am misunderstanding and you are powering down the scope through the Buttons, the other reason settings can get lost or reset is due to the internal battery of the unit going bad that stores the internal settings. I have also seen power surges (especially when using magnetic connections) cause this situation to happen where settings are lost. If it is the scope and not power, it will need to get sent back to Bering.
As for comments on the QR mount holding, the LaRue mount is very good at holding and returning to zero. However, since the rail lug is the front of the scope mount, it should sit 6 slots or more from the end of the rail or it will not hold POI. There is too much mount and scope hanging off the back. For others with the standard Bering mount, they recommend 4 rail slots. If you have it far enough forward, and the handle is tight, and you still are losing POI (and you are sure it isn't your gun), it is time to call Bering. I would call not email and you will most likely talk to Diana or Alek, and they are usually very helpful. I personally get better response when calling 817-453-9966 vs emailing. With SHOT show coming soon, I would try again soon. If you cannot reach them, I would contact the dealer you bought it from to assist. I talk to Bering a lot, and I use the exact same number and don't have issues getting through.
Some people like to say I make excuses for Bering. In reality, I find the answers above solve a lot of the issues. It may not solve Freak on a leash's, but it was worth a try.
I wanted to relay a similar situation that happened to me lately. I have tested every Bering model released in the last 4 years, so I have a pretty good idea of what to expect from their thermals as well as my own guns. I was testing an early Bering LRF prototype and when I would zoom, I couldn't hit a 3' x 3' target. This is with a custom-built AR that shoots sub .5 MOA every day with my reloads. This has to be the scope, right, because when I would zoom, I would miss the target. It wasn't. I put the prototype thermal on a secured tripod all by itself and left it for 4 hours in the freezing cold. Every 30 minutes or so I would zoom the scope. After 4 hours, the image was exactly where it started. I then put the scope on another gun and had zero problems. I was 100% sure the problem was the scope, and it turns out, I had a COL issue on a batch of my loads that was causing a random flyer and it just happened to coincide when I had pressed the zoom button. I would have bet any-amount of money the problem wasn't my gun, and I would have lost a lot of money.