Change:
"-DQT_FEATURE_openssl_linked=ON" ]; <ins> NIX_CFLAGS_COMPILE = [ ''-DNIXPKGS_LIBXCURSOR="${libXcursor.out}/lib/libXcursor"'' ]; </ins> outputs = [ "out" "dev" ]; postInstall = ''

Discussion:
On Wayland (with QTQPAPLATFORM=wayland), Telegram doesn't use the system cursor theme. Steps to reproduce the behavior: Wayland with QTQPAPLATFORM=wayland set how the cursor doesn't use the system's cursor theme and instead uses a simple, small black cursor theme Telegram on wayland should use the system's cursor theme. ! ! Here it's on wayland ! ! Here it's on Xwayland. Also just noticed that it only renders like half the cursor or 75% of the cursor, but screenshots seem to make the cursor render correctly. Please run and paste the result.
I have the same problem on Xorg, it started when telegram moved from Qt5 to Qt6 (not implying it's related to that though).
Same issue is encountered in xorg + i3. I currently pinned package to commit: to workaround this issue.
Contrary to you, I found this behavior in X11, everything works fine in Wayland.
The same happens in , will be good to test it on kde/gnome maybe is something qt6 is using from the desktop?
Happens in too..
+1 for xmonad
Sorry I'm not really maintaining tdesktop now. cc seems to be an issue of Qt6? Personally, I doesn't have cursor issue on sway.
Most likely an issue with Qt6, but I'm also at a loss what to do to fix this. I noticed we had a patch for on qt-5, could that be related? (it even applies cleanly on qt-6) Could anyone do a preliminary test by setting
This still happens on gnome wayland, same as i reported on the original post.
I can reproduce it on gnome wayland.
Ok, so, this also affects other applications: mpv obs-studio PrismLauncher
Any news on this? Still facing this issue :(
I'm using qtile in x11 and hyprland in wayland and it's working fine in both.
it's still an issue, almost opened another bug report lol this affects apps running on wayland mode.
It also happens to me on multiple machines.

Dug into this a bit, I can't figure out what tries to load libXcursor yet, but: running telegram with shows libXcursor being loaded; it also seems like it is in RUNPATH, but I can't see it with chrpath (most likely it's in the rpath of a dependency or something loaded by dlopen) telegram does not seem to call into libXcursor at all (according to ltrace), so it's probably the wrong place to look (unless it's being used as a fallback or something else) For what it's worth, I can't repro this bug (on sway).
Okay, now I've confirmed that libXcursor isn't used at all. libqgtk3 (ie ) links against it. Disabling the platform theme makes libXcursor disappear entirely from the LDDEBUG output. Let's just drop the LDLIBRARY_PATH hack because it breaks things.
By the way, for whoever this is still broken, it could simply be a configuration issue. Just for a sanity check, and to cross-check variables, please post the following information: Qt theme and platform theme in use whether the cursor is broken on eg file dialogs (if not using XDG portals, and especially if using a gtk-based platform theme) whether the cursor is broken on another qt6 application such as syncplay how you're configuring the cursor theme; if not using home-manager, do take a look at what it does and see whether you're missing something that would possibly fix it ()
I don't have this issue anymore, but I do have issues on other applications such as mpv and xwayland games :/
I also confirm the issue is gone. Cursors are working on Telegram.
I use nix as: nixos with wayland nixos with x11 home-manager with wayland over debian and it does not happen to me in any of them, so I consider the issue gone a long time ago.