Materials Pane shrinks on macOS

[MickCrozier]

ArmorPaint version: ArmorPaint.org - v0.9 (2023-03-07) - f11b359 macOS - Metal

OS/device including version: MacOS 13.3.1. M1

Issue description: After restarting ArmorPaint - Material, Brushes, Particles pane gets smaller, while Layers, History and Plugins pane gets bigger. To a point where Materials are no longer accessable. This started in the '03' release of 0.9. I can't reproduce on demand. But seems to happen mostly after I open ArmorPaint from when my iPad loses the sidecar connection. But every 2-5 days of use and I need delete ArmorPaint and re-install (along with importing all my settings etc blahh)

Steps to reproduce: Happens randomly when starting the app. I'm working on info.

Suggest If it was possible to resize the panes, or reset the position somehow would be a great workaround