Collapsible menu behavior changes as browser window is resized past 1920 pixels

[tjwsl]

Describe the bug
In MAAS 3.4, the UI should feature a collapsible sidebar menu. For screens under 1920 pixels wide, this appears to work, but for wider screens (or more correctly, wider windows), the sidebar is no longer collapsible. The "<<" icon disappears and the menu stays put.

maas-ui version
no idea how to find this

MAAS version
snap 3.4/stable rev 32469 (3.4.0-14321-g.1027c7664)

LP issue
No LP filed

To Reproduce
Steps to reproduce the behavior:

1. Spin up a VM
2. snap install maas --channel 3.4/stable
3. snap install maas-test-db
4. maas init region+rack
5. maas configadmin
6. connect to UI and login
7. enlarge and reduce window width-wise and note when the menu bar collapses or becomes fixed
8. maybe WM-specific, but under Cinnamon on a 3480x2160 monitor, snapping the window into a side or corner results in a fixed menu, even though the effective width is 1920. Sliding the window width from there results in the behavior changing at/around 1920 width.

Expected behavior
The collapsible menu should be consistent regardless of window width.

Screenshots

Desktop (please complete the following information):

• OS: jammy 22.04.3
• Browser chrome 121.0.6167.139 and firefox 122.0

[petermakowski]

It's actually not a bug and works as intended. But I'll raise this with the Vanilla team so that they can take this into account when working on the next iteration of application layout. @bartaz @dgtlntv