The toggle group issue, as seen in this issue tracker post: Unity Issue Tracker - Re-enabling game object with "Toggle group" loses information about previously checked toggle is showing as being fixed in 2019.3.
As seen in the comments of that post, it is a game breaking issue for many people. It would be very much appreciated if it could be included in an earlier update rather than waiting until 2019.3 is released.
Thank You!
They state the version where they fixed it (the current code base) and usually they merge the fix back into previous maintained code bases (versions) when it appropriate and doable. So probably you will see the fix in previous versions as well, keep an eye on the change logs they are putting out.
Good to know. Thank you for that info 
So we’re now up to 2019.1.6 and this is still not fixed. The solution is spelled out in the issue tracker so it’s not like it is not known how to fix it. I would really like to know why this fix hasn’t been included yet and still shows that it is fixed in 2019.3, which is probably still quite a while before a stable version of it is available. I’m not the only one wondering, check the issue tracker 
Reproduced in 2019.1.6
Is there anybody from unity to explain why this fix hasn’t been included yet. We stuck in unity 2018 because of this issue.!!!
The issue tracker now says “planned for 2019.2 and fix in review for 2019.1”
Honestly, more than a month to fix what is clearly a show-stopper bug. I get why all the engineering resources are on 2018.3, but it really feels like someone dropped the ball here.
The issue still persists in 2019.1.8f1.