Project overview file upload not working in web browser

Summary

File upload in project overview in web browser doesn't show file selection window

Steps to reproduce

• open a project on gitlab.com
• go to "Project overview" - Details
• click the "plus" button and choose "Upload file"
• in the popup, click the "click to upload"

Example Project

https://gitlab.com/pfiala/fileupload

What is the current bug behavior?

No file selection window appears, i.e. the file upload cannot be performed

What is the expected correct behavior?

File selection window opens as if the same steps to upload file are performed in Repository - Files page (https://gitlab.com/pfiala/fileupload/-/tree/master)

Output of checks

This bug happens on GitLab.com