Steps to reproduce:
When I switch tabs using Cmd+<Number>, numbers 1..8 eight switch to respective 1st, 2nd, ..., 8th tab, but when I press Cmd+9, it only highlights the last tab as active, but the content remains of the previously active tab. When I press prev/next tab (cmd+shift+[, cmd+shift+]) it switches to the next/prev of the previously active tab, not the current one.
Seems to reproduce only with Vertical tabs, with horizontal works correctly (the last tab truly becomes active).
Expected behavior:
The last tab (e.g. 20th) should highlight as active and the content region should show the content of that tab.
Orion, OS version; hardware type:
Version 0.99.110-beta (WebKit 613.1.12)
macOS 11.5.2 (20G95)
Macbook Air M1 (8gb ram)