Yes, we have already noticed this problem on our side as well. It is actually a kind of bug in WordPress core. And the problem is that while our theme is not activated, WordPress takes its folder name and looks for this name in its own themes repository on the wordpress.org website. And it means that we can’t name our theme’s folder with any name hosted there. That is why we are going to rename our theme folder in our next update to something like
xts-tethys instead of simply
tethys. This issue has been discussed for 11 years now here https://core.trac.wordpress.org/ticket/14179
So to prevent this problem from happening now, don’t update our theme while it is not active in Appearance -> Themes. And make sure that your license is also activated in the theme’s Dashboard.