Hello so I had been sent an Illustrator file thru Gdrive to edit, it is a sewing pattern so it's just made up of different types of lines and a few texts. I send the file back and when they checked they saw that the pattern shrunk like the sleeve pattern at 30cm height turned 30mm. They checked the original file, the one they made, and saw that they were working on CM and not MM. I re-downloaded the file and when I opened it was still really small, I went to preferences and changed units from mm to cm, also changed the one in the document setup but it's still the same.
Edit: I can't resize manually because it's a sewing pattern and any resizing may cause a change in the pattern rendering it unusable