I applied the patches and manually updated the info.yml files to include version 10 and I got it to pass upgrade status and install on a version 10 site but it still didn't work.
It was throwing .once JS errors because of jquery.once not being in version 10 (I had alredy changed dependencies from core/jquery.once to core/once but was still getting .once JS errors).
I copied jquery.once from version 9 core to my theme JS folder, added jquery.once files to theme libraries.yml and then my flex slider block worked.
I applied the patches and manually updated the info.yml files to include version 10 and I got it to pass upgrade status and install on a version 10 site but it still didn't work.
It was throwing .once JS errors because of jquery.once not being in version 10 (I had already changed dependencies from core/jquery.once to core/once but was still getting .once JS errors).
I copied jquery.once from version 9 core to my theme JS folder, added jquery.once files to theme libraries.yml and then my flex slider block worked.