Question about Sonnet eGFX Breakaway Box 550

Use the Sapphire RX580 Nitro Plus SE (8GB, High End) with the Sonnet 500 box ->MacBook Pro 2017 (TouchBar)with 10.4. Everything is recognised, but my external monitor (DELL UP2516D) remains "black". Made to run under BootCamp using a script. Anybody got an idea? Here is a screenshot: https://imgur.com/a/Jm4vo7G