I have a Mac running Mojave 10.14.5.
I have an issue with the home Wifi. I have a 400mbps connection. When I start the laptop, the wifi is fine, but at some point, it drops to less than 100mbps, and this affects somehow all other devices (phone, tv) connected to the wifi.
But then just after I restart the Mac, the speed goes to 400 again, on both the Mac and the other devices.