Bind in dropdown doesnt clean label

Hi there!!

Please I have some problems with clean a dropdown’s label after some action.
I connected label and value with two page variables, so when I click in a button I clean a page variable linked with this dropdown, but, the label not disappear. I tried to return undefine and empty string but these didnt work.
If I test with the input text, its work fine.

Can you help me about that? Tks so much

Its work fine on web(preview portal) and doesn’t work in a android device.

image

Could you help me about that please?