Alpha Channels not showing in previews, filters, or video feature list?

I have created many 3D videos with embedded alpha channels.

They were rendered as stand-alone images with transparency as *.PNG files, then encoded into video using the Quicktime PNG codec with transparency support.

I confirmed that all of the videos had usable alpha channels by loading each into a NLE that supports transparent videos.
All of them worked as expected.

HOWEVER

After uploading them to Pond5, I have found the following bug/anomaly in the listings of the files:
• 36 out of 50 do not appear when filtering my media by "Alpha Channel",
• 2 out of 50 do not show transparency on the hover preview.
• NONE OF THEM say "Alpha Channel: YES" on the details below the video on each product page.

Here's one collection of my transparent videos: https://www.pond5.com/collections/2448290-flags

This is only an issue because I do NOT have any way of specifying that the video contains an alpha channel.

So I have a few questions:
• Is this a bug in the video processing?
• If this is a known bug, when can we expect it to be fixed?
• What can I do to have the items corrected?

Hey @AdobeWanKenobi, when uploading files with embedded alpha channels, please make sure to leave the curators a note requesting that the items be marked "alpha channel." This will allow the items to appear when the filter is enabled.

We marked your flag collection as alpha channel. Please note that it might take a little while for these files to index in search with the filter selected.

Additionally, we will look into having our previews contain the transparent grid as a background.

Please don't hesitate to email support@pond5.com with any questions to ensure a quick response.