Client on iOS 12.3 stopped playing video

Server; seafile-pro-server-6.3.13 on CentOS 7

Client: SeaFilePro on iPhone 8 / iOS 12.3

Uploading videos and pictures works as it should.

Clicking a picture opens the picture
Clicking a video downloads the video and then shows a white screen. it doesn’t play the video.
Only log entry I can see is in the gunicorn_access.log:

127.0.0.1 - - [24/Jul/2019:21:14:26 +0000] “GET /api2/repos/6562be4-1225-4ae3-9a18-839a46a1ee29/file/?p=/Beesty/Beesty.Icecream.20190721.MP4 HTTP/1.1” 200 114 “-” “SeafilePro/1 CFNetwork/978.0.7 Darwin/18.6.0”

No entries in any other logs that i can see.

It worked up until a few days ago, where it would play the video when it was clicked. There has been no changes to the systems that I am aware of.

It works on the android client and on an old iPad, so I really think that it comes down to the iPhone client.

Has anyone else seen similar behavior? Any tips on which hidden logs to look at?

Thank you for any tips…

Mads

I missed this info:

I tried to remove the cache via the iPhone general app settings… This didn’t change the behavior.

I tried to remove the app and reinstall it on the iPhone, but there is no change in the symptoms. Here is what I see on the iPhone:

Same here,
iOS 12.4 client 2.9 not willing to play any .mp3 file. but now i get the same blank screen.
Windows 10 client 7.0.1 works file.
I have seafile-pro-server-7.0.7

I updated to seafile-pro-server-7.0.7, and three was a change:

The iPhone client is now able to play one specific mp4 video, but not other mp4 videos.
I can not see any difference between this specific video and any of the other videos (which can not be played). About the same size… Same compression… Same length… Made by the same device…