Hi somewhat confused too, I upgraded to drupal 10 on my dev machine and got almost everything working so almost ready to bring it to production
I Installed tb_megamenu 3.x alpha2 because the 8.x version was not compatible with drupal 10.
But with the 3.x version tb_megamenu on a normal screen works fine, only have to do some css to change background colors, but on an small (mobile) device it is very ugly and not working as supposed:
Hovering and collapsing the submenu's doesn't work, the main menu's are much to high and on a mobile you can't scroll down so you only see the firste 2 items and not possible to collaps.
My question: is 8.x ported to drupal 8, then I can reinstall version 8 again and install 3.x when it is production ready.
Used tb_megamenu for over 10 yrs now from drupal 8 until drupal 9, do not like to leave this excelent menu system.