Alpha Quicktime video Premultiplied Issue

I know there are many threads about Alpha and I’ve read most of them while searching. My issue is, I seem to have the opposite problem that everyone else does…I can’t get premultiplied alpha to work and only straight alpha works.

My setup:
Win10
Server: 2.3.3
Client 2.2.0
Exporting from Adobe AE as Quicktime Animation, RGB+Alpha, Premultiplied

When I play Straight Alpha everything is perfect. I get key and fill outputs through my Ultrastudio HD Mini and it looks great. When I play Premultiplied, I get the key channel, but the Fill channel is given a solid white background for some reason. Most of the threads state that Straight Alpha won’t work properly which is why this is so strange that I’m having the opposite problem. All of my existing assets are premult so I’d like to get this figured out if anyone has any ideas.

Let me know what other information I can provide

<channels>
       <channel>
		 <video-mode>1080p5994</video-mode>
		   <consumers>
			<decklink>
			  <device>1</device>
				<embedded-audio>true</embedded-audio>
				<latency>low</latency>
				<keyer>external</keyer>
				<key-only>false</key-only>
				<buffer-depth>3</buffer-depth>
				<custom-allocator>true</custom-allocator>
			</decklink>
		  </consumers>
		</channel>
    </channels>

edit: I should note that the Premultiplied files work elsewhere just fine.(OBS, etc). Just not CasparCG

I had an issue like this with QT Animation exported on Win. Exporting the same project and settings on Mac would result in a working file. What version of AE are you on? Have you tried exporting through Media Encoder instead of straight from AE?