Upload from PC and download on phone = quality degrade

Hi, i have problem witch onedrive.
I want to backup my library of photos from phone after i post-process it from DNG, photos are almast everytime at 5000x3000px, but when i upload it on onedrive, it change resolution to lower like 2500x1000 etc. When i click - Show Original - it download original size image.

Problem is i cant download original size on phone. It download only that low res. Tried Onedrive App, tied Photo hub, tried web page... Still same.

Any ideas ?