According to this: https://github.com/openwrt/mt76/issues/666 this has nothing to to with the MAC address, but with the MAC hardware. The RE200 series WiFi was/is unstable for years, and the link above gives some insight why this may be (incomplete EEPROM, wrong Tx power settings ...).
When it reads "fixed" at the very last comment it means in the current development version of the driver, not in the current stable release of OpenWrt.