What type of displays are you attempting to connect to your rPi?
When I was setting up a 4" Miuzei HDMI (not DSI) I had some similar problems to what you’re seeing and it took a bit of searching and playing around to get it to work with the ultimate process I found to work was posted here: Hardware known to work with KlipperScreen - #31 by mykepredko
I don’t know if this will help, but if you’re using an HDMI port, this might help point you in the right direction. What I did find is that KlipperScreen can be fairly sensitive to where it is installed in the process.
When I replaced the display with a BTT PI TFT5.0 (a pretty standard DSI display) it worked without any playing around.
Good luck!