A form can be ready in paper format with the IRS but not yet approved for e-file or approved for use by a specific software engine. This is very common, particularly in the early days of filing season.
Form 2555 isn't a very common form, so it doesn't get top priority. Also, most people filing this form have a June 15 deadline not April 15 giving more reason to push it back.
Patience, it's coming.
