Hello Will

As I see are writing about 2 different video posting features:
1. Post video in Timeline app.
2. Post video in Videos app.
Post to Timeline form allows to make a post attaching link, photo and video. This is a direct post inside Timeline app. In the same time you may post new video using Plus Menu -> Video. I this case video posting will be processed with Videos app and doesn't connect with Timeline app. Yes, you should see notification about such video in timeline but this video will be created inside Videos app. Screenshots provided by you are related to creating a video inside Videos app. But at the beginning you are saying about posting on Timeline.

If you posted a video using Plus Menu and the Video block from screenshot №2 has correct settings you should see at least a block with empty player while the video wasn't completely processed. 

Also you need to check whether you have the newest version of Videos app. Block may disappear if something wrong with block's template.

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Best Regards
Anton