Rater agreement calculation vs crosstabs

Hello :) statistic noob here. this is a general statistics question and not directly an spss problem, so im posting it here:)

I tried calculating the percent agreement between two raters two ways:

1 : crosstabs in spss variable A x Variable B
2: simple calculation in spss by making a new "diff" variable (diff = Variable A - Variable B ) and presenting it in a frequency table in spss. From what i understand the percent agreement is then found in the row the value is 0. ( in this case 75,5 or 78,8 % )

Why is the percent agreement from the calculations in step 2 not to be found anywhere in the crosstabs representation?

I find the percentages in crosstabs confusing: where is the percent agreement in this table?

thank you for the help:) Mette