These square pots have thin flat tapered pins and in my experience these are so easily broken should the item be twisted.I would suggest a skewed pot should be replaced preferably by a multiturn variety.This would give much greater control to setting the bias.Just
ensure any pot you fit will take the 100mA needed.
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My V5 board which I received in July 2019 had exactly the same problem: RV2 or RV3 (don't rememember which one)
was bad.
Since no damage was visible, it took some time to find the cause for the low power output.
I first thought one of the IRF510 was dead and changed it, but this did not help.
After measuring the bias of both MOSFETS then, I noticed that one poti could only be adjusted to about 1,5V (i think). If you turned further,
the voltage just disappeared.
When i desoldered the poti, i noticed that one pin was broken. So I think that the path on which the wiper glided become uneven and the poti lifted
itself when turning to much to the left so that the contact of the torn pin got interrupted.
After exchanging the poti to a new one, it worked immediately :-)
