After upgrading from factory img to 21.02 as well as 19.07, Netgear R6350 Wireless settings page for 5Ghz wlan limits max power to only 6 dbm. The reason is this device carries a partition table that takes into account bad blocks on the NAND flash. The partition table, however, isn't read by vanilla OpenWrt. As such, EEPROM offsets might vary between devices (so far only the two sets of locations are
known to be used though).
A simple solution for affected users is to modify the memory address manually in the DTS and build a new image. Unfortunately the posted builds for 0x8000 and 0x28000, but my device was starting at 0x48000.