2018 Mac Mini - a setup can eliminate black screen
Mac mini late 2018 (2020 version)
RX 5600 XT Radeon GPU
I was struggling with the intermittent black screen during boot sequence. Then I have an ideal to plug a HDMI adapter into a TB3/Type C hub with HDMI output. There is not HDMI connected directly to the iGPU or HDMI port of the mini. Instead the TB3/Type C hub is connected to one of the TB3 port. Connect the another HDMI cable directly from Razer Core to the monitor. In this setup, mini will see two display with one of the HDMI adapter plug into the HUB HDMI output. As a result the mini boot into login screen without any black screen issue. There is no need for hot plug, warm plug or cold plug. It just works perfectly fine.
I have created a video so I like to share with you here in this forum
Hope this really helps you