A400Ms and C130s have been going circuits and approaches at many UK airports in recent months.They only came into BHX because the airport was so quiet and it was something different for them. The flights still happen if you check flightradar24, they're just going to different places.
You can only fly the same approach into BHX so many times before it starts getting boring
I tracked a 400M on FR24 one day. It departed Brize Norton then did a tour of Great Britain and the Channel Islands, doing en route circuits and approaches at Humberside, Aberdeen, Glasgow, Guernsey and Bristol before returning to BN.