I have the same leak.
Here's my Triumph America Case Reference #: 00882435
My bike is in the shop for the 3rd time for the leak. They are saying the leak is NOT coming from the bolt that has been getting all the attention. Triumph is telling them to remove the transmission/crankcase cover the bolt goes through. In order to do this, they have to remove the engine entirely. If the cover is bad, they have to replace the cover and case as a pair. As they are apparently matched.
If they say yours is the only reported case, then they're lying or not looking very hard. It appears to be pretty widespread. There are a number on this forum with the problem. Of the four 2020 rockets my dealer has sold, mine is the only one with the leak, but the service mgr said he is aware of the problem with them elsewhere. I smell a recall..We need to make some noise. If this doesn't get rectified soon, I'm going to have to go Lemon Law on them.
Good luck and please keep us posted.