Steps to reproduce:
When the new tab page is set to 'Start Page', then there seems to be a delayed animation with switching tabs while the Start Page is the current active tab.
Tabs switch instantly as soon as you click on them.
Orion, OS version; hardware type:
Orion: Version 0.99.114-beta (WebKit 614.1.12)
OS Version: Monterey 12.2
Hardware: MacBook Air M1
The end of this video recording also shows the bug mentioned here, which I initially thought was due to the slow animations caused by the Start Page, but I have disproved that in this recording.