https://www.chess.com/settings/board
should take you to options (or follow 'Settings' -> 'Board & Pieces' from the links in the bottom left, assuming your setup is the same as mine).
'Animation Type' has various options, including 'Slow'.
I've never tried it, but I assume it is slower than 'Default' which I have always used.
Speed of pieces

How can you adjust the speed of piece movement on Chess.com? The pieces move a million times faster than my brain can think.
The speed of light is still faster than the speed of the pieces which move "a million times faster than a brain".
https://www.chess.com/settings/board
should take you to options (or follow 'Settings' -> 'Board & Pieces' from the links in the bottom left, assuming your setup is the same as mine).
'Animation Type' has various options, including 'Slow'.
I've never tried it, but I assume it is slower than 'Default' which I have always used.
There was a period of time, two months ago, where I experienced this as well.
As far as I am aware of, according to the kind staff who responded to me, the piece movements are unfortunately not adjustable. I tried and tried before that, but ended up emailing Support.
How can you adjust the speed of piece movement on Chess.com? The pieces move a million times faster than my brain can think.