I think I fixed it. I found and installed this beta firmware: https://static.tp-link.com/2019/201912/20191206/ArcherC5400x-up-ver1-1-4-P1[20190629-rel24006]_sign_2019-06-29_18.47.02.zip mentioned in...

I recently upgraded my internet from 300 Mbps down and 30 Mbps up to 600/100. I'm rebooting the router every day as I'm powering it down for the night. After the morning boot, I get full speed both...