CSV and TSV exports doesn't work while XML, HTML, JSON or RSS work perfectly


I’m using Matomo 4.1.x, on-premise.

On all reports, when I want to export:
:x: CVS, TSV doesn’t work: 502 error, reported by the reverse-proxy (empty response)
:white_check_mark: XML, HTML, JSON or RSS work: 200 OK

No error in PHP console or error file.

What can I do? How to diagnose the issue?

Thank you