I have to correct myself. This behaviour only happens if the search phrase is a non existing note, that was already linked somewhere else.
Steps to reproduce
Create link in note like [[Test Example]]
Search for “Test Example” in Quick Switcher
Press enter
I can’t explain why, but in the Help Vault it works, in my personal vault it reproduces the “e.lastindexof is not a function” even though I enables safe mode and shut of all custom CSS.