iOS and Android app won't show uploaded image thumbnails

[ugmac]

Hi there

We just recently deployed Zulip w/ Docker & Nginx reverse proxy. Everything seems to be working except the uploaded pictures won't display their thumbnails properly on iOS and Android clients. macOS and web clients are unaffected.

However, the actual picture shows up fine when tapping on them.

I know similar issues have been marked as 'solved' back in 2018 but apparently something is up with our deployment.

Docker-zulip: 2.1.4-0
iOS Zulip: Latest from App Store
Android Zulip: Latest from Play Store.

Any input appreciated.

[ugmac]

I found out the issue was because of Cloudflare.

Please close

[gnprice]

I have this without cloudflare. Android. Anyone else?

(This report became #4215.)

I found out the issue was because of Cloudflare.

Please close

Sure.

@ugmac I would be quite curious if you can say more about what was the issue with Cloudflare! Including how you determined that was the case, and/or what you did to resolve it. That information could be quite helpful for someone else in the future.

[recklessnl]

I'm currently having the exact same issue, running Zulip through Cloudflare, using a reverse proxy (Caddy), and images are loading just fine on desktop apps and in the browser, but for some reason only on mobile will the thumbnails not load at all. Not even gifs from an URL! When I click on it it will work just fine. Same with profile pics - it shows similar 'default broken image' but when I click on someone's profile, it shows the image just fine.

So clearly the images load once you click on them but not as previews or thumbnails within the Android app.

I don't know what to look at with Cloudflare for this - anybody have any ideas?

[gnprice]

Thanks @recklessnl for the report. Let's discuss in the new issue you filed, #5845.

This might be related to whatever was affecting @ugmac above, but it also might not. One interesting difference in symptoms is that in the screenshots above, avatars (aka profile pics) are showing up just fine, whereas they aren't for you.