Pants are popping through shirt in Metahuman, can't fix...

I’m using version 5.8 and I’m a new to Metahuman. I’ve tried deforming the mesh and nothing happens after I accept then save it to the final outfit. I’ve gone through a few Youtube tutorials on how to layer the clothing but in version 5.8 I don’t see an option to create a “Mesh Component” using the Mutable plugin. Below is a screenshot of what the issue looks like on my Metahuman:

I got these assets from the Fab store, the shirt is a separate asset from the pants and I tried different assets with the same problem (all assets said they support 5.8 and Metahuman).

Easiest thing to do would be to export shirt mesh to an .fbx file, import it to Blender, then use sculpt tool with inflate brush to make shirt fit over pants. Would probably want to export pants too and import to Blender scene so you can see when the shirt escapes pants. Alternatively, you could modify the shirt material and add a texture sample and add a world postition offset to vertices and paint a grayscale texture to map the areas which need inflating. Or for that matter, you could paint vertex colors (if it’s not a nanite skelemesh) and get vertex colors in material and add/multiply a world position offset to it Just paint/erase the vert colors to black, and paint a soft white area along bottom of shirt, Plug this into material, adjusting multiply value as needed: