@Kevin_Z 

It doesn't happen instantly. It takes some time until the channel changes to 149 (sometimes half hour, sometimes a couple hours), but yes, it happens without any interaction, automatically.

I've tried to set 44 once, but the problem happened the very same way.

I'll try to do a factory reset right now, and will come back with a feedback in a day or two (or sooner, if the problem happens again in the meantime).

Thanks for replying!!

@Kevin_Z 

I did a factory reset and then I set the router's 5G the same way it was (160Mhz - 44 channel).

Even doing everything you said, the problem stills happening.

My settings:

After rebooting, the channel went back to 44.

It's kinda strange, because I don't even have the option to select this channel at 160Mhz.

When the channel jumps to 149, my connection drops drastically, to a speed about 0 to 1 Mbps. Just when it goes back to the channel I set (36, 44, 48, or any other), my speed goes back to normal too.

@Kevin_Z I have the same issue! Manual channel selected 48, and always drop to channel 36. Only with reboot its repair, but shortly. PLEASE give us SOLUTION!!!!!