[Vuejs]-Weird Vue linter behavior: "123 {{ v }} 123" within H2 multi-line tag caused error

The linter is complaining about your return characters, notice the return character at the beginning and just after the second 123.

I believe it is saying you should put them all on the same line, ie

<h2 class="subtitle">123 {{ env }} 123</h2>

Of course, I wouldn’t be surprised if there was a conflicting rule on the auto formatter that says not to put it on one line. You will need to decide which you rather. Personally, I would find and turn off that spacing rule because I prefer the formatting you have already.