none of the 2018.x versions from hub is working

i'm attending a game development training course based on Unity, but the version installed there is 2018

the fact is that, at home, i can't have running whatever 2018 gnu/linux version available from the hub - they get installed, they start opening showing a splash screen and progress bar, but always in the end of opening process, all versions closes automatically

so i needed to have whatever 2018 version for being able to work on projects without further retrocompatibility headaches, as at home, as in the training course

it only happens to all 2018 versions, none of them run at all - and instead of that, all 5.x, 2019 and 2020 versions runs perfectly

at home, i'm using Ubuntu 19.04

if possible and needed, please let me know if i can try something for sharing logs and etc.

thanks in advance