While creating custom bbCode, only one <source> tag gets parsed to the final html.

Hello! While creating my forum, I was creating custom bbCodes to implement in posts. These bbcodes allowed me to insert a <video> element to play our videos in a post. I am using them in such a way to embed a Mediaelement player as our html5 player. I am using the quality selector plugin with it, so I need multiple <source> tags that point to various files. In phpbb 3.2 if I inspect the video element in a post, only one <source> tag shows. I tried this code on a custom bbcode on the phpbb 3.2 demo

<div>

<video>

<source src="source1">

<source src="source2">

</video>

</div>

However, trying this same code on phpBB 3.1 demo works perfectly. I believe something may have changed in the bbCode Engine to cause this, but may be wrong. Can anyone verify this is indeed a bug and not an intended feature?

tl;dr I feel I didn't explain this well enough, I'll make a video showing my issue in case I'm not being clear.