Upload issue from iOS app

Hi there,

I’m running a current (27.0.0) release of Nextcloud in a Docker container using the official Nextcloud Docker image. In front of the Nextcloud container is an Nginx reverse proxy with modsecurity enabled using the OWASP Core Rule Set. The problem I’m having only occurs with uploads from the iOS app - uploads using the web interface and Windows desktop app are fine… When uploading a file larger than 150MB, the upload from the iOS app will fail with the error “cannot parse response”, after which the app will repeatedly retry. In the Nginx logs, the following error is displayed:

192.168.1.1 - andy [21/Jul/2023:08:30:30 +0000] "PUT /remote.php/dav/files/andy/200 HTTP/2.0" 499 0 "-" "Mozilla/5.0 (iOS) Nextcloud-iOS/4.8.6"

The app logs on the iPhone show this:

2023-07-21 09:29:40 [INFO] PROCESS-UPLOAD find 1 items
2023-07-21 09:29:40 [INFO] Upload file 200 with Identifier  with size 209715200 [CHUNCK false, E2EE false]
2023-07-21 09:29:40 Network start upload file: https://cloud.[redacted].com/remote.php/dav/files/andy/200
2023-07-21 09:29:40 [INFO] Upload file 200 with task with taskIdentifier 10
2023-07-21 09:30:20 Network completed upload file: https://cloud.[redacted].com/remote.php/dav/files/andy/200 with error code -1017 and error description cannot parse response

Does anyone have any ideas what could be causing this behaviour? I’ve checked the usual limits such as the client_max_body_size in Nginx, but it would be useful to know what differences there are between the uploading done from the iOS app versus the Windows app.

Any help anyone can give would be very much appreciated!

Thank you,

Andy.