...ind, to set it to false, and tried again - it worked. I'd wish that new users wouldn't have to try and find browser.tabs.groups.enabled and activate as it was set to false as default in my case and additionally set browser.tabs.hoverPreview.enabled to false to get it to work again for better UX (user experience). Hope this gets resolved soon. Edit: I am trying out Firefox Nightly which I never knew about until today after looking at other community discussions and exploring. Everything t...