It should re-scale ui and fonts according to diplay settings there it's window located
It still have UI/font scaling from main display
Operating system:
Windows 10 x64
Version of Telegram Desktop:
1.7
Used theme:
Dark
Another variation on this issue. When switching between docked (dual monitors) and un-docked (built in screen only) Telegram doesn't redraw/rescale for the active screen's scale setting.

The same issues are for Ubuntu 18.04 (DE by default)
Another variation on this issue. When switching between docked (dual monitors) and un-docked (built in screen only) Telegram doesn't redraw/rescale for the active screen's scale setting.
More precisely, Telegram doesn't mention any display configuration change and always use the scale from the display it starts from.
I have seen this bug since 2017. Is there any plan to fix it?
maybe this can give a light.
https://doc.qt.io/qt-5/highdpi.html
https://doc.qt.io/qt-5/scalability.html
Most helpful comment
Another variation on this issue. When switching between docked (dual monitors) and un-docked (built in screen only) Telegram doesn't redraw/rescale for the active screen's scale setting.