The first one seems to be indeed a bug, thank you for reporting this so exactly and with the app version number! I'll look into it and try to find a fix.
The second - the app works as expected, the blue progress bar shows the current reading position. It will also reset and show a different position even without reading aloud, if you just open and read text from the screen, scroll to some place (say 50%) and double-tap there to highlight the sentence. Upon double tap, the app may start reading aloud or not, depending on your settings under "Speech settings", but the progress bar will update anyway.