The new feature of leaving the active tab open when you close the group appears to serve no useful function, since it closes anyway as soon as you select another tab. It now takes two clicks to close a group. Please include a config option to disable it and return to the way tab groups worked prior to 142, when closing a tab group ... closed it.
Some of us find this really annoying. I found it so distracting that I've installed the ESR version in parallel to the standard release.