Problems with my ph pens

Sorry I'm new here. I have two digital ph testers
One is a bluelab combo meter brand new
The other is an oak ton
I also have the liquid test kit
The problem I Am experiencing is
Both pens are showing 6.5 6.7
But the liquid test is perfectly yellow
When I used the pens to reach a 6.3 reading the drops were
Orange
I have but lockout or the beginning of it so I know there was
An issue but I'm still not convinced which is right
Both pens were calibrated at the store and both the 7 and the
4 are perfect.
Still if the pens are both showing 6.5 those drops are usually
Light green
Only thing i can think of is that the water is 60degrees at testing point

If you PH pen has been calibrated properly.. it will be accurate.. Those drops give a "close estimate" and often the quality of the reading degrades with shelf life. If you were using the drops before and have nute lock out.. there is a good chance the drops are wrong.. if you just bought the pen.. try it for a while and see if the condition of your plants improve.. i can pretty much guarantee the drops are wrong.. and the pen will be right... Cheers!