I don't know if you all have install Flash 10.1 on MIUI, but I install Flash 10.1 running with MIUI 12.3.1. Sites with flash shows up great. Just as you would see on a laptop or desktop computer. Working flawlessly for me. So if you have not downloaded Flash 10.1, I highly recommend downloading Flash 10.1 from the Market/Apps/Tools and should be the second one down.
PLEASE MAKE SURE YOU DO A BACKUP BEFORE DOWNLOADING FLASH 10.1. (DO IT AT YOUR OWN RISK).