This newly appeared in Ubuntu 18.04 and was not seen in previous versions.
First when we save a pdf from a browser (firefox and chromium), a dialogue box pops up asking us to enter the file name and/or choose a location.
Secondly In previous versions of Ubuntu, this dialogue box could be dragged around to any location on the screen, in 18.04 this does not happen and what is worse the popup dialogue box freezes the entire browser so that one can not scroll down the background page.
This becomes especially irritating as while saving a file I generally give a file name similar to the title of the article, but with this new feature, the dialogue box blocks the title and forces me to do extra work.
Is there a workaround? Can this be changed in upcoming updates?