That “TC=25°C” qualifier is not a thing to take lightly–it’s not exactly easy to maintain when burning 500+ watts in a device half the size of a chicklet… See this post for more info on such topics.
Note that a 50W pot is likely to include a co-packaged inductor for free. Doesn’t seem likely to be The Problem here, but one ignores parasitics at one’s own peril. The potential on that timing capacitor might be interesting to watch along with everything else, perhaps one of the other diagnostic pins available to get some idea of what’s occurring.
I find such problems often arise when there is disagreement between the schematic on the page, the actual physical assembly, and one’s mental representation of such. Spare no skepticism in the search for inconsistencies…