I got this “glass” effect after i applied a material

I got this “glass” effect after i applied a material on some branches in blender 2.91 and it’s not because an amd driver(i have nvidia)
I have 2 branches, and I made a group with those two. The first one worked great, but the second got a bizzare glass effect, and not just that one, after I applied the texture in a copy of the first one, it didn’t work.

I want to mention that the second one didn’t have the body (like gray or something, like the cube from the startup), it was kinda clear.
I have posted this question on blender.stackexchange but I didn’t get a clear answer… and my question to somehow closed or something… even if my problem is different from others…
this is the link, please help me…
( https://blender.stackexchange.com/questions/206321/i-got-this-glass-effect-after-i-applied-a-material-on-some-branches-in-blender )