Diagnosis
This is often caused by "Smart Connect" and DFS radar interference. Smart Connect tries to steer devices between 2.4GHz and 5GHz bands, and the 5GHz band can temporarily shut down if it detects radar signals (common near airports or military bases).
How to Fix It
First, try disabling Smart Connect. Log into the web interface (192.168.50.1). Go to Wireless > Professional. Find the "Smart Connect" section and turn the toggle OFF. This will split your Wi-Fi into two separate networks (e.g., MyNetwork_2G and MyNetwork_5G). Connect your high-speed devices directly to the 5G one.
If That Didn't Work
The 5GHz channel might be on a DFS channel. In the same Professional tab, for the 5GHz band, set the "Control Channel" to a fixed, non-DFS channel like 36, 40, 44, or 48. Also, set the bandwidth to 80MHz for stability.
Heads Up
Splitting the bands means you'll manually choose which network to join on each device. It's less "smart" but far more predictable. If you live in an area with radar, the system is legally required to vacate those channels, which causes the dropout.