There is no Windows 11 driver from AMD for the R9 270.
The final driver was 21.5.2, there will be no newer drivers for any OS version.
Ryzen 5 5600x, B550 aorus pro ac, Hyper 212 black, 2 x 16gb F4-3600c16dgtzn kit, Aorus gen4 1tb, Nitro+RX6900XT, RM850, Win.10 Pro., LC27G55T..