I have the same issue – all events appear twice in the overview.
Opening and saving them resolved the issue, but if you have a lot of events, that’s undoable.
I would appreciate if you do better testing before releasing the updates – every time I update the plugin there are unexpected errors, and it’s getting to the point where I am debating to replace this plugin. I don’t want to, because the functionality is great. So I hope you can design a more thorough test, or work with beta testers so the new versions are more stable.
I had the exact issue in all these browsers: Firefox, Safari, IE and Duckduckgo.
You can resolve it by installing the plugin Enable jQuery Migrate Helper.
“With the update to WordPress 5.5, a migration tool known as jquery-migrate was no longer enabled by default. This may lead to lacking functionality or unexpected behavior in some themes or plugins that run older code.”
Works fine – the Job Manager team should review code so it’s uptodate with the new WordPress versions. I’m on WP 5.6.
