Unable to check all flights at once for an aircraft

In the Flight List for an aircraft I used to put a checkmark in a checkbox for a flight to destination and all the flights for this aircraft to that destination would be automatically checked. Or I would check Select All and all flights would be selected for the aircraft.

Now it won't do it. I have to go and manually check every single flight.

E.g. I want to swap aircrafts for particular route. It used to be easy task to do with just couple of clicks. Now it very cumbersome task as I have to do 20-50 clicks!

Please help with this bug!