In Excel, how do I count how many time a value is associated with values in an adjacent column?

Question

Greetings and salutations! I have a dataset as below. I need to count the number of times each unique Custom Id value is associated with a pair of Move to Thaw/Move to Freeze (known as freeze thaw cycles). For example, the first Custom ID of BS9583621 should have a count of 2, in fact all these in the example image should (but the list is very long and there will be hundreds with more or less than 2).

I tried something like this that I found online for a similar question someone else asked:

=IF(A2<>A1,COUNTIF(A:A,A2),"")

But it's essentially counting the number of times the Custom ID appears.