LoopTools : Wierd shape instead of being a simple circle Anyone can help me a bit with a LoopTool issue? I am trying to turn some square circles I did on a model into rounded one but each time I press the circle option in LoopTools instead of making it look like in the third picture I attached (the expectation one) it just deforms my model as in picture two I am not sure what I am doing wrong and how can I fix it? How can I solve the problem of achieving the rounded circles without having all the areas affected?
(I am new to blender so I am lacking some basic knowledge regarding how the program functions .. please explain the solution as you would do to a newbie) 
Thank you very much for your support!

This is how my work looks before applying anything [ I want to turn that square into a round shape)


This is how it looks after applying the circle effect from LoopTools ( far from what i want and all the edges are affected.. not sure what I did wrong)


This is exactly how i would like it to look but i can't seem to be able to get the square to a circle shape
I had this. For whatever reason it unticks merge in your mirror modifier.