I have used the brush twice since giving it a good clean and it lost around 6-7 hairs each time, some short but others full length hairs. I have contacted the vendor to see if there is any remedy through them.
Question for you, Paules - do you use this brush constantly or is it in a rotation?
I did some fairly extensive brush drying and weighing experiments quite a while back (alas, didn't get around to posting them here yet apart from a few charts), and found it takes about three days on average for a brush to dry out. So I now use a three-brush rotation scheme.
I could surely be wrong, but suspect that early hair loss is due to glue issues and some hairs not being firmly bound, but later hair loss may be due to mold damage or rotting at the base where the hairs are most densely packed and dry the slowest. If I had some that were deteriorating this way, I might be able to confirm or disprove my suspicions with a microscope, but haven't. So this is guesswork.
Now if you never let it dry there completely, maybe something bad could start to happen after a year - a little surprising nonetheless and doesn't explain the shorter hairs being lost that you mention.
Another thing - you say you dry your brushes. How? I shake mine vigorously about 50 times, give or take. I do that in front of a towel, and can feel the backspray against my face. When I don't feel many droplets, it's dry enough. I place them on a shelf away from the sink and shower. Just a few suggestions.
The hair loss on all my badger and boar brushes has been early, apart from two vintage ones which I later re-knotted. So this shouldn't be happening, but the reason is still murky.
By way of update I followed the vendor's instructions which were to give the brush a gentle clean with shampoo and combing the brush when dry to remove any loose hairs. I lost around 20-30 hairs during the combing step and around 5-6 every day for the following week. I contacted the vendor who, without prompting, offered to replace the brush. A new Chubby 2 is on its way to me as we speak. Outstanding customer service from the vendor and, as a result, will have a customer for life. Thanks all for your advice as I tried to resolve this matter.
Contacting the vendor you got it from is your best first step, and that should take care of the problem. If however you have trouble with the vendor, contact the manufacturer. If the vendor fails, the manufacturer will usually resolve your problem.
Have you cleaned it at all in the past 12 months? Sometimes soap scum builds up and causes hairs to break off. I would suggest giving it a light cleaning in a water / vinegar mix (majority water). Not saying this will fix the problem but it could.