Technique is what you probably missing. Try reading a classic like https://www.goodreads.com/book/show/4865.How_to_Win_Friends_...
Bottom line: You can criticize as long as you wrap it up the 'right' way
Bottom line: You can criticize as long as you wrap it up the 'right' way
The book FuNe suggests is a classic and a very good read. I've spent my time as a software developer and consultant in both huge, medium and small companies ranging from 1 to 50.000 employees, and the larger the size, the more the "us vs them" inter-departmental bullshit was present.
If you're the right kind of honest, you could just become a consultant and get paid 10x more per hour for being honest, for some reason people listen way more intensely to someone they pay a shitton of money to voice their opinion ;)
PS: This might read as way too broad a statement or as an attack on British people, rest assured that it's not. I genuinely find the British art of social decorum absolutely fascinating and I think it can have tremendous value. Speaking as a Frenchman, I too often witness the cost of being too hot-blooded and blunt in the social rapport.
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'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.