I'm using Start11 2.51 to set up a vertical taskbar on the left side of the screen on Win11 24H2 26100.4202.
I've pinned the icon for Voidtools Everything to the taskbar and when I open Everything, the entire contents of taskbar shift several pixels. Then when I close it, the whole taskbar shifts again. Bizarrely, this happens even when Everything isn't at the very top (ie. if it's the second or third pin down). All of the taskbar items shift together and it doesn't look like the Everything taskbar item changes its height at all.
Video here - https://imgur.com/a/QkxEhAJ
Please let me know if I can provide any other information or troubleshooting.