According to the official docs https://docs.unrealengine.com/4.27/en-US/WorkingWithAudio/Nativesoundfield/ an ambisonic submix can be rendered to Resonance or Oculus; however when doing so, while the sound is active in the level, no audio is heard. Sending to just Unreal Ambisonics or just Resonance does produce sound.
1) Launch AudioQA
2) Under Assets > Soundfield Submix open SS_UnrealAmbisonics
3) Drag the SS_ResonanceBinaural Soundfield Submix asset into the SS_UnrealAmbisonics graph. Connect the output of SS_UnrealAmbisonics to SS_ResonanceBinaural
4) Set SS_UnrealAmbisonics as the Base Submix on any sound asset. An ambisonics asset can be found under Soundwaves > Soundfield
5) Drag the asset into the editor
Output is silent
There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-172291 in the post.