It happened again, I like the Attila theme and switch to that to test and see if the issue was resolved but it make a third site 😅 I understand we can change our domains, say I change the original to something else, does that free it up to be used for the theme I tried to change it to? Or should I wait for the ability to change themes on an existing site to be fixed? Ty! 
Discussion
I changed mikemonty81 to mikemonty1 and then tried to change mikemonty29 to mikemonty81 and saw the error in the screenshot. So I guess I can’t just change the domain to get the correct theme to display and the domain would be lost to me if I tried to with the current iteration 😅 