I created a default third person template
Created custom trace channel set to block
Created new character class and added a USphere and UCapsule component (and movement functionality)
Created A derived blueprint class of the new character
In the blueprint class I set the sphere and capsule collisions to ignore everything and only block my custom trace channel
The characters started jittering after the first test
So I resorted back to the untouched default third person character and it had the same jittering affect as the new character class
I replicated this in 4.24 and it works fine it only started when I started new 4.25 project