I noticed pixels flickering on a model when moving the camera. Since I could not find the bug / reason for it myself I made up a small demo, where the bug happens (at least on my machine, see screenshot).
Yes I have tried - I found that model has issue ( I try Blender with new cube and flip normal inside. Than I check if pixel doesn’t flicker.
But I don’t know if you have sandbox.fbx has many vertices you should make 8 vertices - if it doesn’t flicker. But I have tried. Nothing pixel flickering.
You can try models by Blender and It has fbx binary 7.4 version. I think MonoGame has bug because latest version of fbx binary 7.5. I will check if it doesn’t work.
It looks fine for me. I think sure you need export from Blender ( Fbx binary 7.4 )
I think the model consists of small square polygons whose vertices are not shared with the neighbours. So I guess what makes it flicker in the end are precision errors of the vertices which are close together.
I have to find out how to texture the model, I am a blender noob
And You will know I have captured about UV mapping = it is no texture - Like it is easy without texture. If you want add texture than you can export UV Layout and export model fbx than you can paint with Substance Painter or open your favorite paint editor like Gimp or PhotoShop.
Than you can load texture into Blender and more… Good luck!