Moto Z2 Play - Navigation buttons not showing up

Good evening,
I just installed eelo on my moto 2 play albus following the installation instructions. The installation proceeded fine (a calendar error occurred during the initial guided setup), however the main buttons are not showing up (Home, Back, Multitasking). Basically my phone is now unusable, since once an app is open it is impossible to exit and go back to the home menu.
I tried sideloading the OS a second time, following again the same instructions, yet nothing changed. Any support is welcome.

Ok, after some googling I suspect the problem was related to the infamous ‘one button navigation app’. I solved it from the side, downloading a simple Navigation Bar app that does its work.

However, now the problem is with my device audio output. To what I’ve seen up to now, only phone calls in speaker mode and system sounds (when tried from Settings, e.g. when trying available ringtones) work. I tried forcing audio output to speakers with an external application such as Lesser AudioSwitcher, but nothing seems to work :confused: