2 frozen left front calipers in 12 months

[aftorwar]

I replaced my left front caliper a year ago (frozen) along with the brake fluid. A year later, the new (reman) caliper is frozen. Seems odd that a one-year old caliper would freeze even if its a reman (A1Cardone). Is there anything else that would cause the caliper to freeze up? The other calipers are fine which leads me to believe its not the master cylinder. I'm going to replace the caliper again but am wondering if there could be another cause.