It's possible. Never known anyone to have this problem. The nut which holds the prop on the vcu spine should have a u shape thing and a washer thats bent over the bolt head, to secure it all together. Maybe the case it was taken apart and not put back propper previously.
When I first checked it did not have the u shaped washer and the smaller washer was not bent over. So I assumed the bolt worked loose and the splines were the weakest link
Today I stripped the joint that has no splines. Cleaned it up with a grinder and pencil grinder. Torqued the welder and went for it. I'll get it fitted to the fl tomorro and see what happens