Since I got a new phone, xperia xz1 compact, my download speed when using USB Tethering has been reduced to 1Mbps.
Upload speed is fine, > 30Mbps.
Doing a speedtest on the phone itself shows a download/upload speed > 30Mbps. This does not happen with WiFi tethering, only with USB.
If it helps, the computer is a Linux machine, Debian 9, which works perfectly fine with my old phone (HTC 10). The HTC was not a Swisscom branded phone, whereas the xperia XZ1 Compact is purchased from Swisscom.
Does Swisscom throttle download speeds when using USB thetering, or is it likely some other hardware-related issue?