I have a 2019 Macbook Air and I use a QGeeM USB-C hub to connect to an ASUS 28" 4k monitor. The Monitor has a DP port and and 2 HDMI ports - one for 4K @ 30Hz and the other 1080p @ 60Hz. I connect to the HDMI port that supports 4k @ 30Hz. I use a Logitech keyboard with the USB dongle connected to the hub. And an Apple bluetooth trackpad. I leave the macbook screen/lid closed and connect to the hub.
98% of the time the 4k resolution on the monitor works perfectly. Every once in a while, the 4K monitor loses its resolution and I can only get 1080p. Sometimes, I can just restart the macbook, unplug and replug the display HDMI cable and everything works fine. And sometimes I end up spending an entire day trying to fix this.
I don’t understand why this happens and more importantly, How might I fix this ?