I am regularly asked about a dogs behaviour that the owner has been enduring for a long time. The issue with this is that because the behaviour has become ingrained modifying it becomes a far greater challenge.
DO NOT WAIT.
If your dog repeatedly does something you deem as undesirable, take action with training/ behaviour modification as soon as you notice it. Not only will you not have to put up with the behaviour you don’t like, but your dog will be far happier because of this.