I think that jack is kaput, as
@Ronnie already pointed out. I would not want to mess with it, just replace the whole thing. I don't know how easy it is to access the bolts that attach it to the frame.
Unfortunately, I think we have a bigger problem with those new 240/242 boat/trailer combo setup, those trailers are way too tongue heavy from the factory.
This was initially pointed out by
@Neutron, and subsequently some here (including myself) moved the bow stop back on the trailer, I think at least 5+ inches is a minimum and it makes it possible to move the trailer around at all. I could not, and would not, move mine around beforehand - dreading the scenario you are experiencing.
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