Performance issue on Rpi5 and Hailo8

can you check if you are running pcie gen 2 ?
you can do that by running the following command in rpi5
sudo lspci -vv
look for the speed of the pcie ( Hailo8) if it is up to 5GT/sec per lane , if its lower then its gen 2 and you have to upgrade to Gen 3.
Guide Link : How to upgrade to pcie gen 3 in rpi5 with H8L M.2?