OK, so, I checked my manual. Subaru calls the smaller center display the "Multi-Function Display" or MFD. The MFD is located above the main center display. The main center display is larger, and is used for radio/media and the reverse camera. The MFD is located above the main center display, and is set further into the dashboard (closer to the front of the car).
There are two MFD types; they vary with the trim of the vehicle. One is black-and-white, with fixed format display areas -- mainly 7-segment displays, and a few fixed symbols. It has similar display capabilities as that of a cheap digital watch. The other MFD type is color, dot matrix, and can display arbitrary graphics (similar to the main display). The Subaru website says the Premium trim comes with the simpler, black-and-white MFD. So OP has this:
(logical page 202, ordinal page 206, file MSA5M2102A_STIS_opt.PDF, dated 2020AUG24)
Note the limited display capabilities. The next page lists lists what the "Driving information display" can show:
Note the absence of climate control information.
So the B&W MFD display isn't going to help OP. I cannot find any mention of climate control information display, outside of the color MFD. The section on the climate controls does not mention displays at all.
Perhaps there is a way to show climate info on the main display (that's how my old Honda worked). Perhaps the manual is wrong, and it does show up on the B&W MFD. Perhaps a climate control readout simply doesn't exist (that would be lame, even for Subaru, but I could believe it).
I would suggest contacting the dealer for assistance.