Just a quick note if somebody from Mac Develop program lands here:
I'm brand new to Apple development, so, maybe this is a common knowledge, but I didn't ran across.
Signed up for Mac Developer program, not iOS, and tried to "Refresh from Developer Portal" with exact same error: "Too few items in teams." Tried all the steps above and elsewhere, with no success.
Ended up calling their support to only find out that this particular functionality doesn't work with Mac Dev only (no iOS Dev) membership profiles. So, manual download/import is the solution as tech on the phone told me that it looks for iOS teams, doesn't find it and errors out.
Hope this helps & saves a couple of hours of frustration for somebody.