SUMMARY

When trying to take a regional screenshot or "all screens" screenshot, Spectacle silently fails when TV is "disabled" inside display configuration.

STEPS TO REPRODUCE
1. Have a TV plugged into system (I'm not sure if it's specifically a TV or just a HDMI source)
2. Disable the TV in Display Configuration
3. Launch spectacle and try and take a "all screens" screenshot
4. See that nothing is captured

OBSERVED RESULT
No screen data is captured

EXPECTED RESULT
Screen data to be captured

SOFTWARE/OS VERSIONS (ran `kinfo`)
Operating System: EndeavourOS
KDE Plasma Version: 6.4.0
KDE Frameworks Version: 6.15.0
Qt Version: 6.9.1
Kernel Version: 6.12.34-1-lts (64-bit)
Graphics Platform: Wayland
Processors: 24 × AMD Ryzen 9 5900X 12-Core Processor
Memory: 32 GiB of RAM (31.3 GiB usable)
Graphics Processor: NVIDIA GeForce GTX 960
spectacle: 6.4.0

ADDITIONAL INFORMATION
I usually have a TV plugged into my system but disabled during the day. Recently tried taking some regional screenshots but, Spectacle would silently fail. 
After a _lot_ of searching I managed to find a thread on the Arch forums with the exact same issue as me: https://bbs.archlinux.org/viewtopic.php?id=306440

After I enabled the TV in the display configuration, I could take screenshots again.

If you need more information, let me know. I would be happy to provide more!