This is something I have reported several times in the pre-threads but until now, I couldn't find the cause of the issue.
My MCP is on a 2nd screen and everytime I move the fader a bit faster with the mouse, the fader lags behind. Turning off tooltips completely solves that issue.
EDIT, just checked, the same happens with a fader in the TCP.
It doesn't really stand out in the GIF, but when tooltips are on, the fader pretty much jumps from one value to another, without any smooth steps in between.