sometimes from the error has occured screen while sometimes in download mode@jalepeno123 sure... screenshots are always welcome!
So, now my questions is... when you tried to use ODIN to flash STOCK firmware... Did you do it from that screen? (i.e. the screen that shows downloading with an arrow pointing down?)
Advice: I know you have two firmwares, but always use the latest, don't use older firmware, if you have flashed newer firmware, especially the Bootloader; it is not advisable. Use this as it is the latest: SM-G975F_1_20201028025634_p90n1mn4i0_fac