Is this (e.g.,, make a cash+miles award booking and get charged twice or thrice for an award ticket) a routine problem with BD award tickets?

I've now observed people being charged (the cash component + taxes/fees) for three award tickets when there were only two passengers traveling (when the understanding was that the amount quoted and authorized was for both passengers combined).

I've also observed one award ticket for one passenger having the cash component + taxes/fees charged twice.