Less RX/TX rate in 2.4 Ghz in 4.1 firmware of ax 1800 flint?

hi im testing the new firmware and seen like the transmit power are a little less than the 3.x firmware, with a 20Mhz channel the 3.x firmware connect more or less maximum in a same device 92Mbps and with the new beta firmare the max Rx/tx decrease to maximum 72Mbps, maybe a driver thing? the transmit power in dbm are the same than the 3.x firmware?

WiFi driver is changed to open source driver and performance dropped a little bit.