That is inaccurate. I first replied that it is normal not to get email notifications when a group is invited, and that is incorrect. Then there were 10+ replies about how group invites should not be excluded from invite notifications ALL OF WHICH WERE WRONG – my fault since I started us down that path. So I apologize if me removing irrelevant information that I myself triggered with incorrect information in the first place, is troubling to you.
In the meantime, as you can see in the screenshots, the feature works correctly and I verified it myself on try.discourse.org. No idea why it does not work for you, since you will not or cannot post screenshots of your relevant post invite email logs, as I have, above.
You have yet to post a single screenshot in this topic of any kind. Until you do that, we can’t help you. Sorry!