Subaru diagnosis help from the Hive?

I'm a member of a group on FB and one of the members posted the following.  I was wondering if anyone here could offer some concise suggestions for the possible cause...  Thanks in advance

I own a 2019 Subaru Crosstrek that I bought new in April 2019 with a 6-spd manual.

I like the car over all. But, since almost new, it's had an issue that has defied all diagnosis and is making me regret my purchase and doubt that I will ever buy another Subaru.

When the humidity is higher - I cannot put any definite value on "higher" - and I'm trying to accelerate between 2000-2800 rpm, it hesitates, has no power and just will not rev. Once it gets to about 3000 rpm, the issue disappears. At times at cruising speed, I can feel it hesitating slightly. It just doesn't run as smoothly as it should all the time.

I'm not lugging the engine - I've got 500,000+ miles on manual transmissions and know how to not lug an engine.

I've had it into the dealer on 3 separate occasions with the problem, but the issue is intermittent enough that they have "been unable to recreate the issue".

There is no "check engine" light when it happens so I can only surmise that the computer believes it be operating in normal parameters but this CANNOT be normal.

On our recent trip, it was unable to accelerate at 60 mph up a slight grade in 6th gear, which it should be able to easily pull. I had to downshift to 5th or even 4th to get the revs high enough to make any difference.

The dealer recently performed an "ignition reprogram" under recall but it didn't fix my issue.

I suspect the dealer doesn't want to put any real effort into finding the problem because of the lower labor rates paid for warranty work. I took the Service Manager for a ride once and I could feel the issue from the driver's seat - lack of power - and invited him to drive but he declined saying he didn't feel anything. I suspect he doesn't know how to drive a manual or just doesn't care.

The dealership recently had the car in for five (5) weeks to replace a shift fork in the transmission and the ignition recall. They were again "unable to recreate" the engine issue.

I know mine isn't the only one in the fleet with the issue because I've seen the same complaints from other Crosstrek owners on a Subaru forum. I emailed Subaru and their response was that they weren't familiar with the problem and that I should take it to the dealer for diagnosis. BTDT.

I think there has to be another level to Subaru service above dealership where someone, somewhere has access to a repository of information about issues like this.

Does anyone have any contacts at Subaru corporate who might care and whose brain I could pick?

Any experience with service-level repair work or higher?

Any shade-tree mechanics want to take a stab at diagnosis?

Thanks in advance for any help or suggestions.

Does the engine have some sort of variable valve timing (most seem to these days)?  E.g. it might be getting stuck in high RPM mode, or moving to it too quickly.

I would think something like that would create a code though.

Is some kind of lemon law claim a possibility? That seems to be the trigger to get something like that escalated beyond "meh, it runs, we don't have time to deal with fixing it".

If there are several complaints online, it's probably programmed in, either for a reason, or by accident.  The dealer is unlikely to be able to fix it.