QubesOS 4.1 Multi-Monitor Telegram Preview Issue

Telegram’s image/video preview window does not work with the QubesOS window manager. Even if I switch to full screen mode first, it cannot be displayed correctly. This is very annoying because it means I have to download each type of media I want to see before I can see it. Is there a workaround for this problem?

How exactly does it behave on your side? In what system (installed in a template) does it run? Which client version?

Asking, since it does work as intended on my end, therefore it’s hard to diagnose without details.

That is very interesting! Which template do you use?

I run my Telegram client in a Debian 12 minimal template. Everything else works fine. I am an advanced user.

If you are on a default template, it might be a minimal template problem.

archlinux

Wouldn’t be surprised if the minimal part was the issue.

After years of not knowing and just accepting that it was a QubesOS bug, I figured it out today! Finally! And completely by accident, but because you made me tinker with it again. So thanks for that!

TLDR: The fix is to put the Telegram application on my laptop screen. While the fix makes it quite usable for the first time since using QubesOS, it is not the solution, so I will not call it that.

Let me give you some background: I have a 4K monitor and a 1080p laptop. I set my 4K monitor as primary and reduced the resolution to get everything up to a manageable screen size since QubesOS does not support fractional scaling. The result is that my virtual 4K display is still slightly larger than my native laptop display. I usually have my 4K display in front of me and my laptop in front of the screen on my desk. When I place Telegram on my main (4K) screen, the preview does not work. The preview window just pops up and shows fragments of the Telegram application.

If I place the Telegram application on my laptop screen, the preview on the laptop screen launches fine. So it is a problem with a wired resolution or the multi-monitor setup itself.

Now that I have figured out the problem and have a fix, we can move on, but what would be the actual solution to using Telegram like any other application I use on my main 4K screen?

The same problem exists in Qubes 4.2.3. The same weird fix works. Does anyone have a better solution?

You need to adjust the VRAM:

Thanks for the information. I never changed the VRAM setting and it worked fine for me until now. After changing it, nothing changed for me either.

The problem with Telegram’s media preview window is that it opens as a new window and shows only a white screen or some artifacts of Telegram’s main window (with the QubesOS colored border around it). It also tends to hide behind the main window.

I tested again, and this has nothing to do with multi-monitor at all, because even on my laptop’s 1080p screen without a second monitor, Telegram’s preview shows the same problems.

My guess is that the window breaks because it cannot expand fully, but is limited by QubesOS’ own window management. Setting the Telegram VM to fullscreen mode does not help either (not even in single monitor setup).

Do you have any other idea how to fix this? For me it’s the most annoying QubesOS bug, because I have to work with Telegram (a shitty application, no question, bad for privacy, but at least I can see the media content on regular Linux).

That said, the title is wrong. It is a QubesOS window management problem that has nothing to do with multi-monitor at all. At least in it’s current state in Qubes 4.2.3. I cannot change the title because it is a very old post. I will wait for your thoughts and open a new post depending on your response.

Thank you all very much!

Maybe it’s an issue with missing package in the minimal template.
Try to use telegram in a standard template and see if you’ll have the same issue there.

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The exact same problem exists in Debain-12-XFCE. I would assume that this is a QubesOS specific window management issue. The preview window does not expand properly.

Other ideas?

I have created a new post with a summary of the things we already know from this thread. I would appreciate it if you would follow up on the new post. Thanks in advance!