Wifi problem with Mac mini M1

Thanks for your explanation and I think I'm now sorted!

It wasn't interference but it was probably the metal frame of my Wacom that was between the Mac and the wifi signal, which coupled with the metal box of the Mac mini was probably blocking the signal to the wifi antenna.

I've just run a speed test which gave results comparable to my other devices.

Reflecting on the issue, I'm truly surprised that the wifi antenna in the Mac mini is so susceptible to things around it, in particular because my other devices did not have this issue at all, even though the objects on my desk were the same.

But, problem solved, so thanks.

Depends on what you mean by 'added'.

I have an external hard drive, and I use a second display, which is a Wacom pen display. However, this has been my configuration since day 1, and I've changed nothing since.

In particular, I have not changed anything between the time the wifi was working well and now when it's working very poorly.

The hard drive and the Wacom have been in exactly the same place and connected for years, but even so I don't understand how they can affect the wifi performance.

Please can you explain why this might be a useful thing to try.

Okay, thanks. I'll try some different combinations to track down some interference.