Switching from Object Mode to Edit Mode with a textured material causes a significant change in rendering preview which makes it very difficult to change the position of a texture using the UV Editing tools.
macOS 10.14.5 with RX 580 eGPU (only way to use current release). No VEGA cards work on macOS 10.14.5.
Confirmed bug on Windows 10 (via another user).
Object mode: correct rendering
Edit mode: rendering has "lost" the texture and gone all shiny. No way to adjust the texture position visually.
Sample file attached. Setup with RPR Material Library material and packed. It happens with all textures and Principled shader as well, not just Uber.