The v2.11 image from the web site should work on a Pi 3B without modification. It was designed for the Pi3 and Pi4 and I have often used it on Pi3.
Were you using the Raspberry Pi imager 2 (the current latest version) to burn the SD card? If so, that could be the problem. Raspberry Pi have changed the way the imager does configurations and it does not work well with custom software. We are working on a new installation method that is compatible with Pi imager 2: Experimenting with Raspberry Pi Imager 2
Otherwise, you would need to try Pi imager 1.9.6 at Release v1.9.6 · raspberrypi/rpi-imager · GitHub