the main reason maybe QCA9880 is not compatible with intel wireless card (my test pc config). if "Throughput Booster" is enabled, the initial wifi connection will break soon under heavy data flow, sometime cause the router reboot. in version 6.44.3, I found the router always reboot with heavy data flow. I downgrade to 6.39.x and 6.38.x and 6.34.x, no reboot again, just connection break.

in the meantime, I also found if "Throughput Booster" is enabled, the router may cost much more power than usual, and that may cause a short time power failure. that maybe the reason why router reboots.

After I turn off the "Throughput Booster", everything looks ok now. router is running 6.34.x, I will try to upgrade it to 6.44.3 later and check if it stable.

before this trouble, "Throughput Booster" is enabled for a long time and running older routeros version, and I don't aware of any router crash, except the initial connection a little unstable.

thank you everyone helps me!

What is "Throughput Booster"?

Edit: And even bigger mystery... Why did you open third topic on this?

According to this spiceworks post it looks like it's an Intel wireless card feature? https://community.spiceworks.com/topic/ ... properties

I have the same issue with my HP laptop. For me it took me months to figured it out till today
Thought it was a wireless channel or router problem, but it only happen when my laptop does speedtest and crash the whole 5Ghz band on all devices. Turn off throughput booster and everything fine now.
Wonder if there are anything on the router side to prevent this? QOS maybe?

Not an MT problem, move on!