I have some questions about conducting a Taylor CYA test (with the disappearing black dot.)

After waiting more than 30 seconds but no longer than 3 or 4 minutes, when I test inside the house, the dot disappears at between 65 and 70. If I test outside in natural light, the dot disappears between 45-50.

My question is, how and where should test? Which numbers are correct for me?

Thanks for the help,
Thelma