The short explanation
A home theater PC feeds a television or projector like any other source, but it behaves like a desktop: it has a resolution list, a color format setting, a refresh rate setting, and opinions about which display is primary.
Where you run into it
Two problems come up repeatedly. The desktop rearrangement: turn the display off and Windows moves everything to another screen, and turning it back on does not undo it. And color format: a PC benefits from RGB or 4:4:4 for text, which many televisions only accept on specific inputs with a specific setting enabled.
Graphics drivers also have their own quirks, including TMDS termination behavior that can interact badly with hot-plug events.
How the DR HDMI 8K handles it
The DR HDMI 8K has an HTPC mode for exactly the first problem, aimed at Windows icon trouble when the display is turned off or resumes from standby — noting that HTPC mode is not compatible with HDCP. Its EDID tables include explicit RGB and 4:4:4 entries for the second, and firmware 1.2 fixed a hot-plug issue on GPUs when TMDS termination is active.
Want to test your own HDMI chain?
The DR HDMI 8K is sold through the HDFury.eu web shop.