where is the profile folder stored when installed via windows store?

My firefox which was installed from windows store says the profile is in its normally installed location:

C:\Users%USERNAME%\AppData\Roaming\Mozilla\Firefox\Profiles%USERNAME%.default-release

When I click the open profile button under troubleshooting information is get a location error. When I try to navigate to it manually I found the Mozilla folder was missing entirely from Roaming.

I looked under C:\Program Files\WindowsApps and found the base installation folder but there is nothing in there about profiles. Clearly there is a profile folder somewhere as it saves all my settings/extensions/history between sessions.

Does anyone know how to access the profile folder in this case?