I MAY have stripped my VTA tower, as turning the adjustment knob seems to make no difference. One of Mat's videos says "this can be fixed". Is that something I can do myself? Also, I have it (I think) at maximum height, but the cartridge (Sumiko Celebration II) BARELY clears the record with the tonearm lifter "up.". I have the unipivot needle as far down as it will go and still allow the tonearm to pivot.
TT is a Rosewood Signature 21.
I raised my tower too far also and the threads appear to be disconnected but there is no grub screw at the top of my Fatboy.
It's very unlikely that you stripped the threads. On the top of the black vta tower knob is a small allen key grub screw used to secure the knob to the threaded post. Give it a tighten and that will fix your problem.
Once your vta height adjustment is fixed, see if you can dial in some additional vta height to allow better cartridge alignment. VPI sells a tonearm rising should you need added height, but before you purchase anything, post some picture of your vta tower and your tonearm sitting on the record.