I've turned off wifi and data on my tablet just now to test it. It is showing me 24 briefings, the oldest of which is 323 days old. However, on some of the flght plans the "Briefing..." button is greyed out so no briefing to view, and on some I can tap "Briefing..." and it wants an internet connection to update, but when I tap "Continue" (with no internet available) it will show the old briefing. Most all of them are labeled "Expired", while at least one is labeled "Invalid" but shows all the data. I know that twice I've I tried it in flight with no success, but that's been a while. My plan was to download the briefing and review the destination NOTAM's before arrival, but the briefing was gone. I'll do some further in-flight testing as it's quite possible it's another Operator Headgap Error.