I have not changed anything yet but wifi is back after rebooting. it seems it load fmac43456-sdio if it cannot find fmac43456-sdio.radxa,zero.txt , but this does not happen consistently.
Here is new dsmeg:
sudo dmesg | grep brcm
[ 6.260632] brcm fmac: F1 signature read @0x18000000=0x15294345
[ 6.284470] brcm fmac: brcm f_of_probe: interrupt could not be mapped
[ 6.290934] brcm fmac: brcm f_fw_alloc_request: using brcm / brcm fmac43456-sdio for chip BCM4345/9
[ 6.296629] usbcore: registered new interface driver brcm fmac
[ 6.298908] brcm fmac mmc2:0001:1: Direct firmware load for brcm / brcm fmac43456-sdio.radxa,zero.txt failed with error -2
[ 6.554495] brcm fmac: brcm f_fw_alloc_request: using brcm / brcm fmac43456-sdio for chip BCM4345/9
[ 6.558917] brcm fmac: brcm f_c_process_clm_blob: no clm_blob available (err=-2), device may have limited channels available
[ 6.570447] brcm fmac: brcm f_c_preinit_dcmds: Firmware: BCM4345/9 wl0: Feb 11 2020 11:54:51 version 7.45.96.61 (be7af2d@shgit) (r745790) FWID 01-a41d86bd es7.c5.n4.a3
[ 6.717275] Bluetooth: hci0: BCM4345C5 ’ brcm /BCM4345C5.hcd’ Patchsome times it will load