5GHz on MR8300 ( IPQ4019 802.11) doesnt work

I will come to the point once again. The MR8300 has 5Ghz issues on the IPQ4019 802.11nac and could be due to the "driver default" signal strength setting. It connects but does not browse all connected devices. It's not just a Windows problem because other Android and Mac devices do it too. This is a problem that was also on the 19.x.x. Could it be unsolvable? I point out that with the official Linksys firmware it works regularly. So it's something with Wrt firmware you can't escape. Please give directions on how to detect the problem and fix it because it is unusable. Thank you.