I have done expensive experimentation with many monitors and adapters and so forth.
I'll keep it simple:
WHAT WORKS
DVI-I Adapter -> VGA -> VGA Monitor port
DVI-I Adapter -> VGA -> VGA to HDMI -> HDMI Monitor port or KVM port
WHAT DOESN'T WORK
DVI-D direct cable
DVI-D any adapter
NOTES
DVI-I direct cable may work.
It appears the digital pins on the DVI port on the mini are not active hence the above methods working while DVI-D does not.
HDMI Solution
BENFEI VGA to HDMI Adapter, 1080P Converter with Audio from Computer/Laptop VGA Source to HDMI TV/Monitor
www.amazon.ca/gp/product/B07K14NR8P/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
This works great with modern monitors, even works with my 4K monitor from several G4 towers and mini. No lag.
I'll keep it simple:
WHAT WORKS
DVI-I Adapter -> VGA -> VGA Monitor port
DVI-I Adapter -> VGA -> VGA to HDMI -> HDMI Monitor port or KVM port
WHAT DOESN'T WORK
DVI-D direct cable
DVI-D any adapter
NOTES
DVI-I direct cable may work.
It appears the digital pins on the DVI port on the mini are not active hence the above methods working while DVI-D does not.
HDMI Solution
BENFEI VGA to HDMI Adapter, 1080P Converter with Audio from Computer/Laptop VGA Source to HDMI TV/Monitor
www.amazon.ca/gp/product/B07K14NR8P/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
This works great with modern monitors, even works with my 4K monitor from several G4 towers and mini. No lag.