Downloaded files no longer play in HIFI when back on Wifi, also how often do I have to log on to play them

Hi,

   I am a big fan of Deezer and use it quite a bit.  Two things I have noticed about downloading files for offline play. The first one and the one that is bothersome.  I download at HQ that is about the same as a high quality mp3 I believe and that is fine , I don’t want to take too long to download and if I ever really began downloading I would not want to have to worry about space.  I notice  when I am back online though when I choose to play those songs whether individually or through a playlist, they play at HQ (the downloaded quality) not HIFI which I much more prefer. Two be clear I download at HQ , steam at HIFI and when songs are downloaded they default to HQ even though I am trying to stream…. Any thoughts ? Changes I could make ? I may just turn around and download in the HIFI quality as I really don’t download many of the songs anyway.
    The second thing about downloaded files is often they will not play at all when not online.  I am often met with a popup saying file can’t play because I am offline.  So I reconnect to wifi (when back home) play a song or two, go back into offline mode and the downloaded songs all work again.  Is this just a ‘thing,’ that you have to log in every day or so to keep your downloaded songs working ?   (This becomes a bit of a thing because these are on a media player; unlike my phone the wifi is not on by default to save battery strength).
      These two things apply to a media player , I also stream on a laptop on which I don’t bother to download anything and every is fine there. Does anybody know if playing downloaded songs apply to end of month\end of years lists (most played songs etc.)?