I have an old Android Box. I have not been able to install Kodi 18. The only one I managed to have on this system is v16. Any "how to" instructions or youtube videos are therefore not helpful as I cannot see what is described or shown. I am not very conversant with Android systems and I cannot figure out things to try to solve them. I need some assistance and direct instruction of how to install v18 of Kodi perhaps I can move forward to installing addons etc.
Seems that you have a "similair" old Box as me ! Kodi 16.1 and Android 6.0.1. I also tried many times with different ways to install a newer Kodi , but nó, even downloads with video-addons seem to work (pop-ups 10%,20%,etc.while downloading) BUT do NOT work, so this box is now a back-up when/if(never hopefully) the new box wich dóes allow Kodi updates has a fault or something. Succes with your old box, hopefully some dóes know an explanation for you !