Window fills the entire screen but isn't maximized

[karl152]

Describe the bug
The update manager window fills the entire screen, but it isn't maximized. Maximizing it doesn't change anything except for the window actually counting as maximized.

Screenshots

To Reproduce
Steps to reproduce the behavior:

1. open update manager
2. observe that it fills the entire screen but isn't maximized

Expected behavior
The update manager is maximized, because it fills the entire screen anyways.

Distribution:

• Linux Mint
• LMDE
• Other (please specify)

Software version:
7.1.4

Logs:

2026.04.28@19:01 ++ Launching Update Manager
2026.04.28@19:01 ++ Initial refresh will happen in 0 day(s), 0 hour(s) and 10 minute(s)
2026.04.28@19:01 ++ Inhibited power management
2026.04.28@19:01 ++ Checking for updates
2026.04.28@19:01 ++ System is up to date
2026.04.28@19:01 ++ Refresh finished
2026.04.28@19:01 ++ Resumed power management

Additional context
I tested this on multiple computers with different screen resolutions. Also this issue is extra noticeable when using the transparent panels extension for Cinnamon, because that makes the panel transparent if there's no window maximized, and that doesn't work with update manager.