Salifert test kit

Hi, I just got my new calcium Salifert test kit which will expire in 2029. However, when I tested the calcium I got 700 ppm of ca. This is my first time using Salifert test kit. The test kit that i used before (aquaforest) still read as 385 as usual and all the things in the tank doesn’t show any symptoms of overdosing of Ca. Are there any chance that the test kit is defects or that I did some steps wrong (I read the manual and re-did it 5 times).