I have had lots of issues with video and adapters the past few years, mostly as I'm forced to use them.  My nvidia 1070 in my desktop has 3x DP1.2 ports and 1 HDMI2.0.  I have 3 displays, so I use the 3x DP1.2 ports, and run those through adapters to HDMI2.0 on my Samsung TV's I use for monitors.  Non-stop chaos ensues during power-down and up every day, something different, every linux desktop hates it.  Often one display or another will freak out, and I end up; having to hard disconnect the adapter (ie, reboot it) to work again or it'll come up stuck in 768x1024 (on a 48" tv...).

I found HDMI doesn't handle DPMS sort of power-off modes as vga, dvi, dp, or most methods of displays to handle soft power-off scenarios, ala just power down displays.  When my laptop powers them down, they remain on with no signal, which seems to just confuse the video card and adapter that both freak out.  This seems to have a profound effect on displaya and video cards that don't realize most displays are now hdmi...

Graphic subsystems are a basketcase these days under linux, mostly because of these damn adapters, dongles, and vendor wars.  Intel, that wants to sell all the things, including the most useless gpu on the earth, injects themselves into everything, and always cause me issues as I can't convince the os to use the (real) nvidia gpu.  Probably the same sort of issue if an intel gpu is around with AMD.  Last I used an AMD GPU some 4-5 years ago, it was an issue.  Nvidia Prime via Intel is still sketchy af.

Even on a dedicated nvidia gpu in a server-ish xeon system, with DP-to-whatever adapters I had nothing but issues.  My latest iteration is my laptop (xps 9560) and a thunderbolt3/usb-c dock with 2x 4k/60hz outputs via one-piece DP-to-HDMI cables.  I still have quirks, but I've learned to work around, and now somewhat understand really odd hardware behaviour enough to reproduce it.  Occasionally I still need to disconnect a display at the DP-to-HDMI cable I use now, which is again oddly random.

I don't like the adapters, but my 48" TV's I use for displays don't often come with DP ports native, and using HDMI comes with power management oddities.  A lot depends on your cabling and even display these days.

-mb