Sidebar state (collapsed or extended) is lost upon browser restart

Steps to reproduce:

1. Start the browser and notice that the sidebar is not extended.
2. Extend the sidebar.
3. Fully close the browser.
4. Start the browser again and notice that the sidebar is no longer extended.

(in previous releases this setting was remembered between browser restarts)

Expected behavior:
When the browser starts, the sidebar should be in the same state it was in when the browser was closed (either collapsed or extended).

Orion, OS version; hardware type:
Version 0.99.124.4.2-rc (WebKit 616.1.14.11.1)
MacBook Pro (macOS Ventura 13.4 build 22F66)