I made an Illustrator 26.4.1 graphic that used the drop shadow effect.
When I exported it to SVG, the shadows became displaced. They were all moved a bit to the top-left. I tried all kinds of alternate exporting and effects settings, always to the same effect.

I knew for certain that I had already done this in a previous Illustrator version, so I downloaded Illustrator 25.0 and tried the exact same thing – worked perfectly!
Some time between those versions, something must have gotten buggy.

When I noticed this, I was on Win10 (Win11 now).