Jeep Patriot CVT slips when going up hills

I have a 2011 Jeep Patriot with 90k miles on it. I’ve not driven it much this summer due to the pandemic, but have gotten it on the road every 7-10 days for a drive around the block. No issues. In July I went out the Shenandoah National Park, and right near the park entrance there’s a bit of an incline. As I was going up and down these inclines ( mostly up ) the transmission felt like it was slipping. If I kept the RPMs below ~3000 or above ~3500 it seemed to get better.

Right before I get to the actual entrance, is the steepest part of the climb and the car was really hesitating the get going, no matter where I kept the RPMs. I thought for sure I would need to get towed home, but after paying and getting into the park, it stopped. I drove about 35 minutes up and down the park roads, and did not have any issues.

I returned home, and had no issues, going down the mountain or on the highway at various speeds. I drove it like I had previously every few days, around the block, maybe 2 miles, no issue.

Then on Friday of last week coming back from an appointment, I was on an inclined ramp getting onto a highway, but at a stoplight. The transmission did the hesitate a few times as I accelerated but was fine after the start down hill.

I’ve done the usual routine maintenance since getting the vehicle in 2013. Noticed no obvious leaks, and the vehicle passed inspection in July.

Any ideas?