I installed Buster Lite on a card. I attached a Waveshare 3.5" LCD screen. (It is known to work when used on another board.) I followed these instructions to install the driver: https://www.waveshare.com/wiki/3.5inch_RPi_LCD_(A) using the lite install command as recommended: ./LCD35-show lite
The system rebooted. I got the worst of all possible worlds. On the LCD screen I see plain white. On the HDMI monitor I briefly saw a very large textual cursor blinking in the upper left corner, then darkness. The large size of the cursor would suggest that the screen resolution was set to match the LCD screen, but somehow the focus was never actually shifted to the LCD screen.
The mystery line in /boot/config.txt that starts out dtoverlay=ads7846 is already commented out. I have looked VERY carefully and the pins are aligned properly.
Help!