Mercury Transmit does not display Cross Dissolve with alpha

Hi,

We’re working on a Transmit plugin for Premiere (26.2.2 Build 3, macOS) , and it turns out that a Cross Dissolve effect, applied to fade-in a part of the picture (from black to full content over a couple seconds) instantly displays the final part of the picture, without showing the gradual alpha transition from black to the final picture.

Turns out the same happens with the “NDI output” Transmit plugin. However, the “Blackmagic Playback” Transmit plugin properly displays the same project with the correct fade-in transition correctly, gradually going from black to the full picture.

Is there some part of the Transmit plugin API that controls this, and that we’re missing? Perhaps a specific video format must be used for the final rendering to contain the fade-in transition? We’re using `PrPixelFormat_BGRA_4444_8u`, but I have tried several other formats, including v210, with seemingly the same results. Perhaps some of the suites from the API must be used to request this?
Thanks.