Wrong keys on internal Swedish keyboard A few weeks ago I had a problem with the § and &lt; keys being "mixed up in software" on my external Windows keyboard, (the keys are in the right locations physically). I thought the 10.15.2 update resolved it, but now alt+2 on the internal keyboard produces ™ but it should produce @. It used to work fine, problem started some weeks ago, perhaps coinciding with me using the windows keyboard more often... Macbook pro mid 2014 retina, 13 inch.
The Apple input source called Swedish has ™ at Alt 2.  Same for Swedish Sami PC.

The one called Swedish Pro has @ at Alt 2.

So make sure the list at system preferences/keyboard/input sources has only Swedish Pro on it.