Looks like even I have been effected and we use a different brand. Purolite.
Last 15L DI lasted 5 months before the resin creeped.
So filled a new 15L DI and did the double DI trick. After 2 months the second DI is already creeping yet the first DI is taking the water down from 8 to 3. So the second DI had only got to polish 3 TDS!
I Think more resin is being used in the world and we are getting a bum deal.