Changing keyboard layout when using a vertical panel and 200% scaling disorganizes the layout of the panel

Distribution

Mint 21.3

Package version

Cinnamon 6.0.4

Graphics hardware in use

Intel Iris Xe (Integrated graphics)

Frequency

Always

Bug description

I put my cinnamon panel vertically on the left side. I also use 200% UI scaling.

I use two keyboard layouts (English (US) and Spanish (Latin America)) and swap them using Win + Spacebar or the keyboard layout applet. I dont use 'country flags' as keyboard layout indicator.

If I change keyboard layout (with the applet or key combination), the applet area of the panel is displaced to the right, being visibly off-center. It doesn't come back to its original position unless another event happens that redraws the applet area (e.g. a bluetooth device is connected) or I manually move the panel to a new position.

While in this off-center state, any applet pop-up is also drawn displaced to the right from its natural position:

Steps to reproduce

1. Launch the 'Keyboard' application. Go to Layouts tab. Add "Spanish (Latin America)" as a layout (in addition to whatever layout you already had before). You should have 2 layouts. Disable the checkbox for "Use a country flag, if available ..."

2. Right click on the cinnamon panel. Click on Move, and select the left side. The panel should be positioned vertically on the left.

3. Launch the 'Display' application, set "User interface scale" to 200%.

4. Reboot and log into your account.

5. Press Win + Spacebar to change layouts. You should see the applet area of the panel being displaced to the right, and being visibly off-center. Alternatively, you can change layout manually using the applet, the weird behaviour also occurs this way.

6. Press Win + Spacebar again. The applet zone should move again, and it still is off center.

Expected behavior

The layouts are changed, the applet shows that the layout has changed but the panel retains its layout.

Additional information

If I use a horizontal panel, it seems to still act a little weird, like it creates a little bit of horizontal padding in the layout indicator, but it's not that noticeable. When using a vertical panel, it's evident.

Additionally, sometimes the layout indicator is not rendered at login, it only appears once I hover over it (the space is preserved, it looks like an empty space), but this doesn't happen always.

Reproduce the issue using the Keyboard application, a vertical panel, and 200% display scaling, then compare layout changes made with Win+Spacebar and the keyboard layout applet. Inspect the panel and keyboard layout indicator entry points; done means changing layouts no longer displaces the panel applet area or its pop-ups, including after login.