Can you program the phones to the different bases? Example you have Base A and Handset A, then Base B HS B and Base C and HS C. Can you take HS C and program it to Base A, and HS A to Base C? This is just to see if it's the base or the HS that is causing the issue.

Also, are all 3 bases located in the same spot? Or are they in different areas? Where the poor reception one could be getting interference from something close to it.

KOT