I was analysing better and I guess the problem was not in the M21A but in the M1 !
The LED used is the Osram W1 that normally causes this kind of problem, specially with smooth reflectors.
To minimize the effect, you can try to screw a little bit more or unscrew a little bit the bezel of the flashlight and see if it solves the issue. However, I cannot guarantee you that it will be OK when pointing it towards a white wall. Another solution would be changing or modifying the gasket (that white piece around the LED) but that takes much more energy, time and resources and is a try an error exercise.
I can tell because I had that issue when I modded my Eagle Eye X3R and my Convoy S2 with this kind of LED.
If you use it outside you will not feel it too much, though.
So, looking at to your initial questions, it is annoying but given the difficulty to center this LED in particular, it can be seen as “acceptable” in a certain way.
You can find some more information on this thread: