Hey there, I formatted my PC twice due to this issue.
I tried a bunch of solutions, from here in the forums, other forums, thought it could be my GPU(NVidia GTX 1050 Ti) but...it seems like it's something going on with Solus itself. I tried with Pop!OS and it recognized the HDMI display effortlessly.
What could be wrong? I already installed t he nvidia drivers, didn't work, used DoFlicky, didn't work. Tried these:
https://discuss.getsol.us/d/9121-hdmi-not-detected-by-xrandr
https://discuss.getsol.us/d/5528-issues-connecting-second-monitor-via-hdmi/2
https://discuss.getsol.us/d/6916-hdmi-port-not-working/4
Still nothing, xrand doesn't recognize the HDMI1 port, nor any other than my built-in display. I'm at a Dell laptop.
So...I don't know what else to try.