That is surprising to hear.
I've got a few of the V1 clash rackets, and I was surprised by how stable they feel for their weight, and that's coming from someone who owns a bunch of heavy rackets like the Volkl C10 pro and Head prestige tour. However, I did add a leather grip to the 100v1, which brought the racket to 305g unstrung.
I now own a Clash 100v2 but I'm yet to string it up. I've read a few posts of people saying that it is much firmer than the V1 despite only being a few RA points higher on paper. I'm hoping that it's only a very minor change in feel.
I wouldn't think its the flexibility in particular that's the issue in your case though though. I've used unstable rackets of all stiffnesses, and I agree that it doesnt feel great. Wilson's quality control is so bad that my swingweight may also be totally different to yours, which may explain our differing perception of its stability.