You appear to be using the beta or dev insider release of Windows 11.
The latest version of that has a bug relating to not showing the show hidden system tray icons button which is causing Start11 to also hide the system tray icons which would be visible.
Obviously we do not offer formal support for insider versions of Windows 11 for this reason as bugs in the OS have unexpected consequences.
The issue will go away no doubt with the next Windows insider update or next Start11 update whichever appears first. Obviously a Start11 update will not fix the show hidden icons button not showing as thats a bug in the OS, but the other issue caused by that would be resolved.
The other option is to turn off the enhance taskbar feature in Start11 as this will stop the Start11 issue at least.