Steps to Reproduce:
Go on https://commons.wikimedia.org/wiki/Special:Upload
Try to upload a file, or to overwrite an existing file.
Error message, file not uploaded.
Request from - via cp3060.esams.wmnet, ATS/8.0.8
Error: 502, Server Hangup at 2021-01-27 09:10:12 GMT
Note that Upload Wizard seems working instead.