Don't know if this issue is being dealt with on another Thread as I couldn't find any.
Have installed OpenATV-7.4 dated 14 May 2024 on Octagon sf8008.
When I installed a skin, it appears to install correctly and is indeed shown at /usr/share/enigma2.
But, the installed skin does not then show up in the Skins Menu for eventual use.
On OpenATV-7.3, installed skins feature correctly in the Skins Menu.