Hello @v-mengmli-msft ,
I can't help myself but wonder what do you mean it is a browser issue not a Power Apps issue.
Setting autocomplete to off for the entire browser eliminates even useful autocomplete for users such as their addresses, and as @brown_1892 correctly pointed out, we just cannot ask users to turn this off just because Power Apps team developing modern controls omitted this basic attribute (although the control is still in preview).
To further support that this is most definitely Power Apps issue, please see this MDN Web Docs describing that autocomplete can be set on individual input level or form level. By extension, I believe this definitely points towards a choice while developing modern control text input to leave out this attribute.
<form method="post" action="/form">
…
<div>
<label for="cc">Credit card:</label>
<input type="text" id="cc" name="cc" autocomplete="off" />
</div>
</form>
<form method="post" action="/form" autocomplete="off">
…
</form>
Link to MDN Web Docs - How to turn off form autocompletion
I just wanted to add this since in our experience is that this is hell of an annoying feature currently since it seems to be collecting all previously entered texts completely unrelated to the currently selected input.
BR
Wiliam
