On my phone boost plays the video in preview, but not when I open the post

Thats true for me too, but if I click to open in an external app, but choose Boost, it does play

Had this problem a lot in recent weeks.

This is snoozemaxxing. She has good form. Obviously seen a lot of reps.

Don’t know why I replied I’m on Voyager

This specific one works fine for me, but I have seen this behaviour before.

Does it have something to do with network connectivity? I have a somewhat aggressive DNS blocking system, which breaks some uploads. Does the direct embed need some connection that visiting the site directly doesn’t? Is there a delay that makes the embed think the link is dead?