IzaacB

It works weird in 1.19.41 with maps as well.

Try this:

/give @s empty_map 1 2
/testfor @a[hasitem={item=empty_map}]   <--- No targets matched selector
/testfor @a[hasitem={item=empty_map,data=2}]     <--- Found IzaacB
/give @s filled_map 1 2
/testfor @a[hasitem={item=filled_map}]    <--- No targets matched selector
/testfor @a[hasitem={item=filled_map,data=2}]     <--- No targets matched selector