Cannot upload large video files to Google Drive

Using Firefox 88.01 (64-bit) and since the last couple of days I cannot video files (about 1 GB or more) to my Google Drive folder. Files of small size, like text files sized about 50 KB or 10 KB can be uploaded. The error message I get on the Google Drive Page is "Starting upload" but the uploading doesn't begin. This happens both in Windows 10 and Ubuntu 21.04. I refreshed Firefox and also tried uploading the file in Troubleshooting mode but that didn't help. Google Chrome can upload files to Google Drive just fine.