My 6 month and 21 days old purebred showline german shepherd puppy's ears haven't stand yet. His one ear is standing up almost the whole day,the other one is still floppy. My breeder told me that there is nothing to worry about and suggested to wait 1-2 months and they will both stand up straight. He told me that the teething period has almost been finished and its normal for his ears not to be strong enough to stand. What's your opinion? Should i do something or just wait?