Here's my WiFi 5G configuration. Nothing extraordinary: What device are you using? Setting gain manually should only be used for devices where antenna can be detached. Otherwise you should use TX Power and leave gain to default. It's MikroTik hAP ax^3, currently with 7.14.3. I didn't enter antenna ...

I have the same router and smartphone, the wireless connection is very stable with 7.18.1! Post your configuration… Here's my WiFi 5G configuration. Nothing extraordinary: set [ find default-name=wifi1 ] channel.band=5ghz-ax .skip-dfs-channels=10min-cac .width=20/40/80mhz configuration.antenna-gain...

I have same issue on MikroTik hAP ax^3 with ROS 7.18 and Samsung Galaxy S24 Ultra. With ROS 7.14.3 it works fine.