1080 Footage leaves small black bar

So, I just switched to Resolve from my old Premiere/AE workflow and I love it. But I'm having this weird issue where the footage I'm working with doesn't cover the whole frame.

I'm using a mix of footage, from Canon 5D mkIII hacked with magic lantern (using the raw files) and also footage from Sony A7 sII and some VHS footage converted into ProRes. This small black bar is consistent through out the timeline and is not affected by the type of footage I'm using.

Scaling the footage scales the footage as expected but the black bar is still there. And this also ends up on the final render.

Project settings:
1920x1080HD (EDITED: WROTE WRONG)
For 1920x1080 processing (EDITED WROTE WRONG)
Pixel Aspect: Square

Image Scaling (if it matters)
input scaling: Scale entire image to fit
Output
Match timeline settings
Mismatch.. Scale entire image to fit

Just ask if there are any specific settings I should list.

Thankful for help!

Project setting should be 1920x1080.

Sorry, I wrote wrong- the project is.

Try the Center Crop setting in your resize options.

Did you verify the black bar is not in the video or if the video's aspect ratio is different from 16:9?

Almost looks like a transcoding artifact; No chance all the footage was transcoded prior to import?

Sorry, I wrote wrong- the project is.

If source is 1:1 aspect and 1920x1080 then there is no way Resolve will add back bars for 1920x1080 1:1 project. It can be juts a fact that Resolve viewer is resized in way that it's not 16x9 (but you said it's also on export).
There has to be something wrong with your assets (maybe wrong headers).
You can upload small problematic sample file or at least show mediainfo (text view) grab for such a file.

Erik, what codec are you rendering to?

thanks everyone for taking the time to read, it's weirder than that because it's only THIS timeline in the project that is affected. I didn't realize this at first but I solved the problem by simply copying all the clips in the timeline and pasted it into a new one.

still have NO idea why this weird thing happened..