Vero 4k won't upgrade from 17.6 to 19 (or anything else) - hotfix applied

i’m trying to update to the latest, I’ve applied the hotfix from the v19 FAQ page, but the update still shows it’s up to date:

osmc@kodi4k:~$ sudo apt update
Hit:1 stretch/updates InRelease
Ign:2 stretch InRelease
Hit:3 stretch-updates InRelease
Hit:5 stretch Release
Hit:4 stretch InRelease
Reading package lists... Done
osmc@kodi4k:~$ sudo apt dist-upgrade
Reading package lists... Done
Building dependency tree
Reading state information... Done
Calculating upgrade... Done
The following packages were automatically installed and are no longer required:
  armv7-libcrossguid-osmc bluez libapt-inst1.5 libbind9-90 libdbus-1-dev libdns100 libdpkg-perl libgif4
  libgnutls-deb0-28 libhogweed2 libicu52 libisc95 libisccc90 libisccfg90 liblwres90 libmicrohttpd10 libmysqlclient18
  libnettle4 libntdb1 libplist2 libpng12-0 libpsl0 libssl1.0.0 libwebp5 libwebpdemux1 libwebpmux1 libxtables10
  pkg-config python-dbus-dev
Use 'sudo apt autoremove' to remove them.
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.

same thing happens when trying to update in the UI. it just runs and says that it’s already up to date.

You can’t upgrade an install that old at this point and you would need to perform a full reinstall in order to update it to the current release. You probably can make a backup and restore to the clean install for most of Kodi’s settings but guisetting.xml might be an issue. Sources and the database should restore okay.