Poor signal in both wifi modules ZBT WG108 router - MT7621

Hello, we have tested the latest stable version of openwrt firmware 19.07.2 on the wg108 router from the official openwrt page at the following link:
https://downloads.openwrt.org/releases/19.07.2/targets/ramips/mt7621/openwrt-19.07.2-ramips-mt7621-zbt-we1326-squashfs-sysupgrade.bin

It works correctly on the Wg108 router we only found a problem with the wifi modules the wifi driver does not increase the output power.

There is poor performance in both wifi modules. This problem turns on the mt7603 2.4ghz and the mt7612 5ghz.

I installed the compatible firmware for the zbt-wg108 router "openwrt_ZBT-WE1326_V7" and the 2.4Ghz and 5Ghz wifi modules work correctly. This firmware runs on Linux kernel 3.10.
https://drive.google.com/drive/folders/1ZFfQQ-7KYNgKc53z_G3_8BOW8Lcl0oEp

Extract the drivers (.ko) of the wifi modules to test in the openwrt 4.14 kernel "openwrt-19.07.2-ramips-mt7621-zbt-we1326-squashfs-sysupgrade.bin" and the problem of tx power remains.

I am attaching the firmware files for possible help to solve this problem.
regards

Start by comparing the mt7603 2.4 GHz and mt7612 5 GHz behavior in the openwrt-19.07.2-ramips-mt7621-zbt-we1326-squashfs-sysupgrade.bin image with the attached openwrt_ZBT-WE1326_V7 firmware and its .ko drivers. Done means identifying why transmit power remains low on both modules and confirming improved performance on the ZBT WG108.