Clear and concise description of the problem

I find it not work when i use documentByxx as the first argument, it works in onMounted, but I can't use the result in my template，I find use watch Api with flush: post, maybe dom element not a reactive element, get null , In addition， a lot of components ref.value not the element, maybe $el, I think provide a function to get the elem or compatible other circumstances

Suggested solution

start listener in nexttick or use onmounted inside

Alternative

No response

Additional context

No response

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