New Monitors, D6000 HDMI not working

[djsdisplay]

For four years on two Macs - previous one was AMD64, current one is M1 - I ran three monitors on the Dell D6000 with 3 Dell UltraSharp U2412M 24-Inch monitors at 1920 x 1200 (these are not hires) - with 3 display port cables and the HDMI port converted to RGB by a short dongle.

I replaced the Dell monitors with VA2456-MHD 24 Inch (1920 x 1080) - also not hires, but upgraded to IPS and 100hz refresh. Should be no bandwidth issues.

All three ports will work for a while - but when I powerdown and undock the mac, when I come back and reattach the HDMI won't activate.

When I fiddle with all sorts of things it eventually starts working, but I can't figure out why.

Everything is the same. Same firmware on the dock. The only changes are different branch of monitor and the lack of the HDMI => 9pin conversion adapter

It also happens on Windows. Tested multiple cables - so that does not appear to be the problem.


I've tried:

moving the HDMI port between different monitors.
completely replaced the HDMI cable with a new one
Reinstalled the display port adapters.
Even re-tried the HDMI to 25 pin dongle.

Sometimes it works, mostly it does not.

[Bah434x]

I had exactly the same issue with this dock, it was great until I added monitor 3 then wouldn't play. replaced it now for Alogic and that works with no issues