SAL1650 - loose zoom ring

Hi,

After one year of intense usage, the rubber zoom ring of my beloved 16-50 is getting loose. Actually its size (diameter) is growing. Please see picture below.

I've had the same problem with the 18-250.

I own a large number of old Minolta lenses and none is showing this behavior. Is this a common problem with Sony lenses?

Thank you for reading