I've noticed that my recorded footage was slightly lower quality/pixelated when the footage is played while fullscreen in a video playback software. However, it was perfect quality when windowed, even when entirely stretched out across the display, as long as it wasn't dedicated fullscreen.
This problem persisted across different recording software (OBS Studio), different games and different video playback software.
After tinkering with the settings of Action! trying to find the problem, I decided to change the Video Size setting to "1080p" and "21:9" respectively instead of "Original".
I then discovered that, using these settings, Action! apparently records in 2524x1080 instead of 2560x1080.
Using these settings fixed the problem with the lower quality/pixelated image, but there are now 2 black bars on the far left and right side of the recordings, where there should actually still be recorded footage. These black bars are probably the missing 36x1080 pixels. (Because 2560 - 2524 = 36)
To further prove this, in OBS Studio, when I choose 2560x1080 for both my Base Resolution and Output resolution, OBS says that the aspect ratio is 64:27, while it should be 21:9 (which actually correlates to 63:27, not 64:27). And, just for comparison, when I choose 1920x1080 for both my Base Resolution and Output resolution in OBS Studio, it says that the aspect ratio is 16:9, which is normal and how it should be.
Seeing as the problem persists across different recording software, different games and different video playback software, I assume the problem is related to either my monitor or my display settings in Windows 10. However, at first glance, my display settings seem correct.
I have no idea what to do next.
What could be causing this and how can I fix this?
Thanks in advance!