In the 1.16.30.52 changelog, it was explicitly stated that blocks with flipbook textures had gotten support for animated PBR maps. In this version it does in fact function correctly, which I used the version files that I had kept on hand for use with a third party version switcher to demonstrate and test. Since that version something has broken the functionality (possibly the new texture set system). Attached I have 2 videos that record the same block in the same world, with the exact same MER and height maps other than the heightmap formatting change. 

Steps to Reproduce:

1. Open a world in version 1.16.30.53 with Ray Tracing on, using the provided Smoker Resources - 1.16.30.53 pack
2. Place and light a smoker in the world, observing how the emissivity animates
3. Open the same world in version 1.16.220.50+ with Ray Tracing on, using the provided Smoker Resources - 1.16.220.50 pack
4. Observe the lit smoker in the world and how the emissivity no longer animates

Observed Results:

As the changelog stated, animated PBR maps functioned correctly in version 1.16.30.53, with the emissivity animating correctly. In version 1.16.201 and version 1.16.220.50+, this does not happen. The emission map only uses the first frame of the animation, leading to a weirdly static fire on the smoker. 

Expected Results:

The functionality of the feature has been present in previous versions of the game, and is currently not on the official Ray Tracing known issues list. Due to this, it is expected that the feature work properly to allow for resource pack creators to use it as a powerful creative tool once again.