I added the center channel and rear speakers back into the configuration, and then created a new measurement file and selected only "Rear Right" or "Rear Left".

The results were the same when running the room correction, the speaker displays:
Radio 40
Radio 87
Radio 65

without generating any sound.

Anthem AVM70, 271, DSP7200x2, DSP7200.2HC, DSP5200x4, JL Audio F113,
Oppo UDP203, Panasonic UB9000, Kaleidescape Strato E, Apple TV 4K,
HDFury Vertex2, Epson LS10500, Stewart Filmscreen 110"