I am not able to load my Vaadin application in Chrome, because it says that cookies are blocked.
However, Cookies are enabled, no extensions are installed, the cache and all cookies are cleared, I hard-reloaded the page, I restarted the application etc. etc.
Basically, I’ve tried every suggestion I could find on Google, but none worked. My Chrome version is 79.0.3945.130 and the problem appeared overnight.
And I should add that this problem only appears in development mode when running on localhost. The application, when deployed on a remote server and running in production mode, works just fine.
Your setup is a bit more involved than usual - can you eliminate Joomla and reproduce with Chrome/Vaadin only? If yes, then the next step could be to install your OS and Chrome from scratch on a virtual machine and if that works, then my bet is that somehow your Chrome cookies aren’t properly cleared.
Sorry, my idea was related to the complex setup above with vaadin running inside an iframe. (there it could be solved from e.g. apache adding the missing SameSite attribute if it’s the culprit) This shouldn’t be the case for your setup!