with the new UI I can open the DEVMOD from the Steam library after the PLAY. It's a minor thing but adding a shortcut in Desktop and press it, it only opens the game not options to GAME and DEVMOD, if someone can help me with that will be appreciated. Thanks.
I put explanation here: https://forum.studio-397.com/index.php?threads/new-ui-faq-and-hopefully-answers.68318/
It worked, I had done it before but the start in was ..../rfactor 2/Bin64 instead of ...../rfactor 2 it made the difference it seems. Thanks.