Plenty of free translation tools around if struggling to make heads from tails when on a site in an unfamiliar language.
The only Scandinavians who frequently encounter me in a personal capacity and seem to insist speaking Danish to me no matter what are the Danish grandparents of one of my godchildren ...... and I think it’s because they assume I have been living in Denmark for a long time since they see me at a lot of family events in Copenhagen and even hours away within Denmark. They know I’m not Scandinavian but I think they don’t get that I more easily understand more spoken Swedish and Norwegian than Danish. For most all other type of encounters, it’s pretty much by default that most Swedes hear my English-accented version of words and try to switch to English or ask if they should do English or Swedish. Danes in Denmark seem more intent to default to stick to Danish with me than Swedes are to stick to Swedish when talking to me.
While most Swedish people — or at least those who began their schooling in Sweden — are able to understand and speak English to a very decent extent, it can be mentally taxing to many of them and there are plenty who are insecure in communicating in English (perhaps because they had bad grades in it in school). The notion that Stockholm Swedes are doing some kind of “Swedish” thing with the website language selections strike me as not focusing on what this is more likely to be about than some kind of discomfort with English.