On Forge 1.18.2 - 40.2.21
Paraglider 1.6.0.6

The stamina wheel does not render correctly when you increased "maxStamina" and "maxStaminaVessels" parameters in server config.
I tried with maxStamina = 9000 and maxStaminaVessels = 30 but stamina wheel still showing only three wheels as before. I think have to be almost nine wheels.

Is it possible to fix this? or adding a client config file to edit the showed number of wheels?

The wheels are fixed at 3 at max value, it is intended. An unfortunate consequence of having to use set texture.

New 1.21 port will have more flexible stamina wheel renders, with support for wheels beyond 3 as well, but since 1.18 is no longer maintained it won't get new features.