Does your intake move up and down freely? Or is it fixed in position? Your intake should be able to move up and down freely since the disc needs space to change directions from being flat to angled when going into and up your intake. If your intake is fixed with no ability to spring up and down then the disc is fighting your robot trying to go up.
I noticed you have rubber bands tied to the shaft for the bottom flex whneels to the standoffs. I can’t tell if you’re using them as a spring mechanism to keep your intake in proper contact with the discs while allowing your intake to spring up and down. But from what I can see it looks like your intake is in a fixed position and doesn’t springs up and down.
There are some great posts here on intakes, but I don’t have time to search through all of them. A great post recently by Vex recently on substitutes for Flex wheel intakes has videos showing the intakes in action and springing up and down as they take in the discs. Flex Wheels Updates From VEX