Just a very quick and minor one, in game all TUI flights have the IATA code X3 prefixing their flight numbers, for the UK originating flights this is incorrect, TUI UK has the IATA BY which should prefix their flight numbers as TUI UK holds a separate AOC, that of Britannia Airways, hence the BY code.
As I say, this is not a bug as such but a minor correction
EDIT: Just in case all TUI airlines have the X3 IATA or for future destinations. Here is the TUI group by destination and it’s associated IATA
TUI UK- For UK Destinations: BY
TUI Belgium- For Belgian destinations: TB
TUI Netherlands- For Dutch Destinations: OR
TUI Nordic- For Scandinavian Destinations: 6B
TUIfly- For German Destinations: X3