Facebook Pixel is tracking the display of the PushState page but with the wrong url

I'm trying to use history.pushState

to simulate a pageview that Facebook Pixel supports:

https://developers.facebook.com/ads/blog/post/2017/05/29/tagging-a-single-page-application-facebook-pixel/

Let's say I make a request https://example.com/original-url

. The Pixel Helper browser extension and my browser tools are reporting a request made something like this https://www.facebook.com/tr/?id=123&ev=PageView&dl=https%3A%2F%2Fexample.com%2Foriginal-url&rl=referring-url&if=false&ts=123&v=2.7.17...

(note that the parameter dl

specifies the URL of the page I'm on).

Then a call is made from that page history.pushState({}, 'Foo', "/foo")

. My browser url has been updated to https://example.com/foo

and I can see an additional request per pixel, but the query string contains the original url of the page, not " /foo

" as I would expect. For example. it still looks like this. Only the identifier has changed.

https://www.facebook.com/tr/?id=456&ev=PageView&dl=https%3A%2F%2Fexample.com%2Foriginal-url&rl=referring-url&if=false&ts=123&v=2.7.17...

It seems to me that this is not correct, as if it writes the second pageview to /original-url

when it needs to write the view to instead /foo

.

Any experts with experience in this area have any comments or explanations?