Question Need help for Z print quality problem

[Bral]

Print 2 models, The textures that protrude from the surface are not at the same height, What is the problem? How to fix it?

 

[Sanity Agathion]

Hello, this looks like something is blocking Z motion. Did you lubricate Z rails? Did you put foam on panels to prevent Z belts from rubbing on side panels? Are all 4 Z belts tensionerd evenly? Are Z modules assembled correctly?

Can you freely move gantry up and down or is it binding somewhere?

 

[Sandman50]

Could also be a rail bolt not tight.