Has come up with a solution all credit goes to her.
From her post,
"Here's how you fix the wonky nesting:
Forum profile icon > My Settings > Preferences > Linear Layout > Threaded > Save Changes"
I tried it and it works and it even works retroactively. Thanks again Fallen Angel Brass!
There's also another way to fix this nesting problem.
I did this fix below and it fixed it and it also does this retroactively.
ETA: I'm using Edge on W11.
From a thread a week ago:
Solved: Forum Posts nesting under wrong comments - Welcome to the Etsy Community
Seriously, I think it's changed the sort on you guys.
Top right of this thread, "options" with an arrow, click it and make sure it says "sort by topics"
What I found: It works differently on Safari than it does on Chrome. If one doesn't work, try the other. Even if the settings look fine, hit SAVE.