Any Way to Turn Off Tumblr's New Embedded Video Autoformatting "Feature..?"?

Hiya! I've just started having this issue, and am wondering if there's any way to work around it. Also, I'd love to know if this is just a temporary thing, 'cause I'd LOVE for this autoformatting nonsense to desist.

In Tumblr, you used to be able to drop the URL of one video into a post using the main Video post section, and then embed the code for -another- video (an entirely separate video, I mean) in the body/"description" of the post; so you'd effectively have 2 different videos in the same Video post.

Well just recently I've been trying this, and -every,- -single,- -time- I open up the HTML editor, drop my code into it, and close the editor again, bloody Tumblr changes my 2nd desired video right before my eyes into the same one that's in the main url of the post. I've literally watched the preview image change from one video to the next, and no matter how many times I've tried over and over and over again, it keeps happening.

At first it struck me as a glitch, or perhaps that my browser needed refreshing, or maybe that Tumblr was doing maintenance. But it seems at this point like it's some sort of maddening new 'feature' they've installed. :P

Does anyone know a way to get around this..? Some sort of way to undo or temporarily block their forced new autoformatting..? Or does anyone know if this'll be temporary? Part of what I liked about Tumblr was that it was a bit adaptable, and didn't treat its users like total bewbs. Please tell me that's not changing in Tumblr-land, too...

Cheers!