cor giving odd result

I am trying to run a cor and a cor test. the cor.test works fine, but when i run the cor it gives a weird result.

I run cor(PreschoolDataUpdate$PQA, PreschoolDataUpdate$GAPQ) and it gives result
[1] NA

I tried making a tribble of the two so there would be no NA or blank spaces in my data set and it still have NA. Any advice?

Check if there are any NA in the tribble.