No signal on external monitor after sleeping or restarting. Consistently "fixed" by resetting NVRAM

I have a 2018 Mac Mini running macOS Monterey 12.6. The Mac is connected to a single external monitor using HDMI. Whenever the Mac wakes from sleep or is restarted normally, the monitor has no signal. I am still able to ssh into the machine when this happens, but there are no displays listed. Using a different external monitor from a different brand, using a different HDMI cable, or switching to a USB-C connection does not fix the problem. The only thing that consistently fixes the problem is restarting the computer and holding down the keys Cmd+Opt+P+R to reset NVRAM. However, this only works for one restart, and the monitor will say no signal again the next sleep/restart. I look at the NVRAM variables after the reset and the only variable that seems potentially relevant is HW_BOOT_DATA but it is not clear to me how to interpret that data. I would like to find a solution to this problem that does not involve resetting NVRAM and restarting.