Bootable USB not working: Goes into internet recovery mode when I select the USB

After several attempts to fix a problem with Big Sur, I deleted volumes "Macintosh HD" and "Macintosh HD - Data" from my drive in order to enter recovery mode and perform a clean install for Big Sur. I have created a bootable USB drive with a seperate computer, but when I try to use it to reinstall the OS on my mac, it immediately brings me to Internet Recovery Mode. Internet Recovery mode does not work, and gives me -2002F error. I have tried CMD-R, it brings me to recovery mode. When I plug in the bootable drive I hold option, which brings me to the bootable drive but when I click the arrow to launch from the USB it brings me to internet recovery mode. I have also done CMD-Option-P-R, but it did not fix anything. Appreciate any tips that I have not yet tried!