WPS Office! By far the best PDF viewer and editor available on the Google play store in my opinion. With the help of this you can view any type of file, let it be PDF, ppt, word document and it also has an inbuilt feature of editing also. So you can change the data whenever you want and can upload it on Google drive from which you can access it from your computer. It provides all the features of a PDF viewer too.
After resetting that feature, text reflow returns, and you may get the highlights If u come back to normal mode, it will return to normal, and you won't see the highlights.