Skeletal Mesh is not updating with the new texture and is displaying in grey

Issue:
Could you please help me:

1- Import the “Mechanical.fbx” file and all associated textures into “UEFN”.

2- Open the “F_MED_Mechanical_Engineer_Body_T1” material, apply the texture, then click Apply and Save.

3- Issue: The “F_MED_Mechanical_Engineer_mo” Skeletal Mesh is not updating with the new texture and is displaying in grey.

4- Note: This was working correctly last month, and the Skeletal Mesh was updating with the new texture as expected. I tried a few different fbx file.

4- For step-by-step instructions, please refer to the following URL:

Who should I contact to fix the issue. Please advice. Thank you