Edit placements Dropdown for text fields is broken
Clicking on the dropdown does not activate it.
Other field types do not appear to be affected.

May be a leftover bug related to bs5 upgrade
I can repro. Strange issue if it's about BS5 because it renders the same HTML elements as on other pages.
@daveblack101 is the other dropdowns underneath work fine?
I checked about half of the others and they were working.
Last question are you working on nightly builds? If Not please have a try may be an upgrade issue in a specific version
I noticed it in 1.5.0-preview-16930
BTW I did some changes recently in the dropdown, but it was related to the arrow color. So, when you tell some are working I didn't expect it's from my PR
Let me share the PR, then check the build before, may be something weird happen
https://github.com/OrchardCMS/OrchardCore/commit/39188a341cea790e7a73b294f3febebc66bf3ccf