need to stick the orderly dropdown under the heade [closed]

When i scroll up my shop page work correctly, the only problem is the orderly dropdown, when i scroll up it not "vanish" under the header like everything in the site (the text near the orderly dropdown - _ result visualized - work too).

before scrolling up

after scrolling up

i found a solution to completely "hide" the orderly dropdown but i prefer to found some better solution because i want it on the page