New Media added to existing project looks bad. Resolve 17.1

Hi Guys,

Apologize in advance if I sound confusing, I am not a native English speaker and I am also new to Davinci Resolve and video editing in general.

I am having an issue that I can not fix.
I have an existing project in which I want to add few more media files. I imported them in Davinci Resolve 17.1, created a new bin folder then added them to the timeline. Once I drag the files to the existing timeline the image looks very low in resolution, much lower than the project itself, really bad.
No matter what resolution I set the timeline to, I get the same crappy footage from the new files which are recorded in 25 fps, 4k DCI, 10 bit MOV on Lumix S5 camera.
The older files in the project are a mix between LUMIX GH4, 4k UHD, 25fps, 8 bit, MOV, and Lumix S5 4k UHD 25 fps, 10 bit, MOV.
The project is set at 4k DCI, 25fps.

Are there any ways to fix this?

If I create a new project and only add the new files to it, everything seems to work perfectly. They are at full res, but I do not want to start the same project from scratch again.

Thank you.