Data validation with filter

Good evening I would need your help for a data validation formula
In the attached file I used the formula:

= OFFSET (Sheet2! $ J $ 2; MATCH (A4; Sheet2! $ K $ 3: $ K $ 81; 0)

but, while in the first two validations of A4: A5 from the desired result in B4; B5
with the choice in A6 the validation of B6 alone gives a name instead of 3 as listed in column D.
Thank you