What is so difficult to understand about the OP's post. It is indeed strange that AC sometimes does not issue electronic BPs because they claim documents need to be checked even if they don't as you got an electronic BP for the very same flight with the very same documents just a week earlier and at the same time they issue an electronic BP for an airport where electronic BPs are generally not accepted.
As for online vs. print: I personally try not to have a printed BP. For one it is a waste of paper and it is one thing less I need to worry about. Also, I never had an issue with an electronic BP and except for my phone battery being low which is entirely my fault/problem and very easy to fix.