I have an HTC One M8S, running Android 6.0.1, HTC Sense 7.0. Internal storage on this phone is 16 GB. I have installed a 64 GB SD card.

My issue is that "Play Store" keeps telling me there is not enough space to install new apps. If I open the "Storage" menu, the phone says there's 15.8 GB saved internally, while there's 3.7 GB saved on the SD card. I have configured all apps that need to save larger files (Spotify, Podcast Addict etc.) so that they store data to the SD card, yet it seems that this space is factored in when calculating available internal storage space.

I can confirm this when opening the "increase available space" dialog; under apps, the dialog shows that e.g., Spotify uses 3.4 GB of space.

Any way to overcome this, ideally without rooting my phone?

Edit: OK, so now I went ahead and deleted all those extra files (downloaded Spotify content, Podcasts etc.) from my SD card, and reformatted the SD card to convert it to an "internal storage" SD card. I thought this would maybe make the errors go away - by forming a single storage space for all types of files; but the problems/messages still pop up. Would be really good to know any documentation/guide on how to do this properly.