So I've been researching and it seems to be an issue with Disney+. While using Netflix and other apps I get Dolby Digital, for some odd reason Disney+ uses LPCM. Using HDMI ARC didn't fix the issue either. Tried to contact support and they were clueless. Does anybody have a fix for this issue?
As I explained to another user, this is not an issue but it's the way it behaves because the app is not coded to have the Dolby Digital Plus to Dolby Digital conversion support as Netflix and Prime Video do.
You should contact support again and ask for that conversion.