I solved the problem by completly uninstaling Tainacan and installing it again. Only remaining problem is that I had to “recover” every block on every page where tainacan faceted search was placed.
That is an annoying but unfortunately common error when transitioning from version to version. Our components use a dynamically loading strategy that depends on filenames which are build by hashes and they change from version to version. What usually happens is that either the browser or some caching plugins store a version of the script that is incompatible with the new one. This is why the message suggests reloading to clear the cache. Uninstalling and reinstalling the plugin may have triggered something that effectively cleared the cache layers.
We’re glad you were able to solve it, sorry for the inconvenience!
To add to the above, sometimes it’s also useful if your site is behind Cloudflare, to clear all cache files there (CloudFlare) before trying anything else.
It has happened to me in the past that’s why I would like to share this