The majority of problems seem to be most people don't understand how to run a variable pitch propeller at all.
Read the stuff in the FAA Pilot License manual, and learn how a constant speed propeller is supposed to be used.
You keep it at higher RPM, as someone mentioned around 80% might be reasonable. When the airspeed is low, you keep the pitch shallow, giving the blades lots of leverage against the air. As airspeed increases, you can increase the pitch to adjust for the motion, and give the propeller bite over the forward speed.
If you have this at RPM while the airspeed is low and dump high or reverse pitch into it, you are putting many many times the stress it can be designed for into it. You don't instantly adjust the pitch, you do it over at least a small amount of time, to allow time for the RPM to do the work.
It is very similar to a Dremel tool. If you use pressure, and lug the motor to do the work, you can easily ruin the Dremel or bit in no time. Instead if you use light pressure, and allow the RPM to do the work over time, it works better and will last.
Realize too, the maximum specs of this. It's a 10" prop on this listing, and 100W motor. What 10" normal prop would draw 100W on a smaller motor like this? Maybe a 10x04? You shouldn't exceed whatever it is, until you're unloading some in the air from forward speed. Most people are probably setting these up with way too much maximum pitch in the first place, far beyond what it can actually do.
Do your math. 10" prop goes 31.42" around for a turn. So a 10x10 prop would have a rise over run of 10/31.42. Rise/run of 10/10 would be 45 degrees, 10/31.42 is less than 1/3rd of that. So about 15 degrees. And that's for a 10x10 prop, way more than the 10x04 or 10x06 maximum throw you should have on this motor, so about 8 degrees. Bet most people are setting this up for 45 degrees pitch, far, far beyond what it should be. That's fine for blowing air at low RPM when at low throttle, but it's a ridiculous pitch at running RPM.
Do the math and you'll realize almost no one is going to be setting these up with as shallow throw as needed. Thus the problems are often user induced, from not doing the homework and having way too much pitch throw.
Shallow, light passes, and let the RPM do the work with lower load on the motor and the tool/prop. Exactly like a Dremel tool..
Note that's near the edge, so maybe 50% or more more in degrees, for the average closer in. But still won't be 45%, which a lot probably have it set to or close.