PWA on IOS Safari does not bring up the 'Sure you want to submit this form again?' alert after submitting a form and gesturing back (by swiping)

On my site, on the regular safari browser on my phone, if I submit a form, go to a new page and then swipe back to go 'back', I get the 'Are you sure you want to submit this form again?' confirmation.

When I use the exact same site, but via the progressive web app home screen shortcut, doing this same thing does not bring up the confirmation box, and it just submits the form again.

I know this could maybe be avoided with things like the Post/Redirect/Get, but it seems like overkill.

I like the 'Are you sure you want to submit this form again?' dialog, it works perfectly.

Why doesn't the PWA do this? Is this a bug/common issue people face with PWAs? Can I disable swipe gestures in the PWA altogether to get around this? I can't find anything else on Google mentioning this specific issue.

UGH!