Video embedded in PDF won't play when PDF posted to web page.

I've inserted a short clip (9MB H.264 mp4 720p 24fps mono) into a large PDF (30.8MB, 340pgs).

In Acrobat Pro the video plays when clicked, and all controls work.

I shared it with a colleague for whom the controls worked.

But when I uploaded it to a WordPress website, the PDF displays and scrolls beautifully, the video poster image displays, but the video doesn't play when clicked.

I wondered if the poster image was somehow blocking the 'mouseup' command when clicking on the video window, so I tried a workaround: I used the Button tool to create triggers for play, pause, mute, rewind, which I placed below the video window. Nada.

In doing some research I read a few comments suggesting that when a PDF with an embedded video is displayed online,  the link to the video content is not kept intact — even when the original raw PDF had the video embedded.

Does this mean I need to have some kind of Adobe Cloud service to store + link + activate my PDF video?

Please tell me I don't need to spend yet MORE money on Adobe to make the tools I'm already paying for work!

SYSTEM:

MacBook Pro 2018

OSX Mojave 10.14.6

Acrobat Pro DC v2020.006.20042

Gratefully,

Luke