I just installed two GFCI outlets that from the farend of the switchbox are in the master bathroom, then the spare bathroom then the garage (that already has a GFCI). I am getting power from both the newly installed ones and the test feature and reset work appropriately on both on them. However, in the master bathroom when I use a GFCI outlet tester, it flips both that outlet and the new one in the spare bedroom. When I use it in the spare bedroom, it only flips that one and not the one in the garage. Why is the master bathroom causing both new outlets to flip when a GFCI outlet tester is used but doesn't occur when using the built in tester.