I also tried brcmfmac43455-sdio.clm_blob with a version from raspberry, but with the firmware-brcm802111:20210315-3+rpt3 the Rasperry P4b debian bullseye stopped working. I then went back to the version http://raspbian.raspberrypi.org/raspbian 20210315-3 and with that the wifi works again. It was not to be brought with 20210315-3+rpt3 to the run. Whatever has been changed....