For my laptop (AMD Radeon RX Vega 10 / Win 10) I use an ext. Screen at the desk (21: 9 / 2560x1080) and every now and then to watch the film my big TV (16: 9 / 1920x1080?).
In order not to constantly reconnect the HDMI cable on the laptop, I got a simple HDMI splitter / amplifier (1 in to 2 out), but did not think of the different formats. If only one device is plugged into the splitter, the display is correct, the 21: 9 is not distorted, the Win display setting is automatic. 2560x1080.
If both devices are plugged in, the picture on the 21: 9 is displayed stretched (even with TV off). The resolution 2560x1080 has disappeared from the list in the display settings and can therefore not be set manually.
When trying out / plugging in, the monitor was also correct when both were connected after switching to TV and back again, however, see above.
Can I forget that because of the technical logic not possible Or can anything be added, expanded, updated, etc. At Läppi? Is there a switchable splitter odaso? Better TV via Wi-Fi maybe or mirroring or what or how?
If so.
I think a USB> HDMI adapter will solve your problem. For example this:
StarTech.com USB32HDES USB to HDMI adapter (USB 3.0, slim, 1080p, external graphics card, multi monitor adapter) https://www.amazon.de/...00H91BQ7Y/
I haven't tested it in combination with a 21: 9 monitor, but it's worth a try.
Of course, only resolutions that both monitors can handle can be reproduced if both are connected. Imaging is still the responsibility of the graphics card. There's always only one picture per connection, no matter how many ports the splitter has. The fact that some blatant renditions are created does not fail to appear in different formats.
