Maybe you've been away for too long? :-)

Are your colleagues mostly Swedish or English/other? Do you speak in English or Swedish to them?

I can imagine if you speak English better than your colleagues then you might imperceptibly/unintentionally treat them like people less intelligent than they are due to having an accent. As a British person working in Europe I've seen it happen, non-UK colleagues I know to be very intelligent are treated ... differently... when talking to someone who speaks english natively. Maybe not "toxic", but in a way I wouldn't appreciate.

I speak English at work, but I couldn't possibly have a superiority complex, they all speak English better than I do.

I think we found the problem. You're a raging capitalist and the Swedes are a bunch of commies.

I'm joking obviously, but maybe you'd fit in better back home. What's toxic in Sweden might be ambitious in Britain. Cultures are different.