"Sweden is known for being the most left-leaning government in the EU"
I agree it is very left leaning.
"but right-wing populist movements are gaining traction there too."
Same with many parts of Europe, same with the world quite frankly including the US because Biden isn't necessarily liked by the average apolitical American.
"Jimmie Akesson is a prominent leader of one of these movements and one of the reasons why such movements are becoming popular in Sweden is because many believe that the leftist governments of Sweden have been too liberal on immigration therefore they want stricter immigration policies."
How many people do you think actually believe in Right-Wing Populism in Sweden? If you know, you can send me the link of your source