IAH-FRA last year on LH. Upgrade from C --> F. Looked perfect till the LH strike hit and this was the first flight out after it ended. Showed zeros across the board and was told ... not a chance. Then right as boarding started I noticed one seat now showed 'blocked' in F and I asked as they were ready to scan my BP. Well ... turned out the EF block was correct and I got the last F seat as I walked on the plane.