It turns out, was influenced by top media query where the position was absolute.
Kailee_Lak answered on June 10th 19 at 15:44
Why dancing with the js? position: fixed works relative to the screen regardless of the attachment in the DOM, you don't need to transfer, just media to change css properties
Austyn.Kunze72 answered on June 10th 19 at 15:46
If you want to make it always appear at the bottom of the viewport regardless of page scrolling, the answer is above. If you need to move to the footer, it is better to add to footer another room and display it using @media queries