I have a Internet box plus, with a Swisscom Internet S package. I'm not expecting our speed to be impressive, but I should have up to 40 Mbit/s (5MB/s) download/upload speed, and our neighbourhood is supported for 1Gbit/s speeds according to the Swisscom address checker. Running the Swisscom internet test, as well as dslreports.com's speedtest, I get the following results:
Swisscom: DL = ~2.13Mbit/s, UL = ~0.1Mbit/s
dslreports summary of multiple tests:
Bizarrely, I get the same results when connected to the router by LAN (Fiber) or WiFi. So my network connection is great. Our upload speed is a problem though: video calls and online games constantly drop out.
I have manually updated the router's firmware to the latest version and rebooted the router, with no improvement. As mentioned, I have also tested the connection via LAN and WiFi (on a macbook pro), and I get the same results with our Nintendo Switch (WiFi).