mac mini multi-display reconfiguring repeatedly
Had similar issues for awhile, resolved via...


Changing combination of adapters / cables / ports as underlying ASICs (Application-specific Integrated Circuits) seemed to have different preferences / properties / thresholds.
Disabling 'Energy Saving' / 'Eco' / Etc. mode on connected displays.
Connecting displays to non-'eco controlled' (master / slave) outlets on surge protector / UPS (if using one).


My assumptions are (and flag if you wish to, anyone ; ) a combination of utilized ASICs in active / passive adapters &amp; cables ± the state of software / hardware development and compatibility across vendors.

Some references which outline the spec as well as some of the same / similar issues below but, essentially, getting Apple, VESA / DisplayPort, DisplayLink, third-party vendors, etc. all on the same page and playing perfectly nice with each other can be… 'tough'.

(Apparently I can't actually share all the links to the references so… workaround = shared Evernote here.)

P.S. Since my case did involve (1) actual USB DisplayLink device [USB w/ DVI-I Dual Link-to-HDMI adapter then HDMI cable to display] in addition to (1) Mini DisplayPort-to-HDMI cable + (1) pure HDMI male/male cable, that’s a lot ICs and muxing in the mix there, only one of which was declared DisplayLink, so who knows what’s inside the others? Perhaps installing the newest DisplayLink drivers resolved multiple issues, therefore might suggest as a potential #4 scenario. (Driver download link is the last one listed above. : )

https://www.evernote.com/l/AASmqLZN5kZFsLnjD1VoDbLASs0i0w4O29U