The HDMI Forum, responsible for the HDMI specification, continues to stonewall open source. Valve’s Steam Machine theoretically supports HDMI 2.1, but the mini-PC is software-limited to HDMI 2.0. As a result, more than 60 frames per second at 4K resolution are only possible with limitations.
Neofetch says that it’s seeing an AMD ATI Radeon HD 8730M and an Intel Haswell-ULT, which is probably the chipset connected to the i7-4600U, and I’m assuming what 99% of the graphics are being generated on.
Try making the move to Wayland. I habe zero issues cinnecting or disconnecting monitors.
If I can do it while keeping Cinnamon, and my current desktop, I might.