Resetting the modem through the web UI doesn’t really work from what I can understand. I had set the band to 3 and it didn’t reset when I run the AT preset “Reset modem” (AT&F0) from the UI.
This one below and a reboot brought back CA!
I’m now at 45Mbps down and 20Mbps up which is a bit nicer, but still a bit far from the advertised CAT6 speeds 