Theme is not applied after 'use', despite CSS file is downloaded to the theme folder

Hi

I am just trying to change my theme but somehow it seems not possible anymore. Before filling this Bug Report I could change the theme used on the Obsidian Help Vault. But after five minutes when I wanted to change it again nothing happens. How is it possible to debug what is happening or is this bug known and I did not find it? and in that case my apologies…

Steps to reproduce

Simply Settings > Appearance > Theme > Manage > Use a Theme

Expected result

The theme I chose is applied to the Vault

Actual result

When clicking on use the theme CSS is downloaded to my $config/theme folder, but nothing more happens. The old theme is still applied but the new one, at least the CSS, is downloaded to the theme folder.

Environment

macos BigSur 11.6
Obsidian 0.12.19


Additional information

An antivirus with Ransomware protection but also there no error message.