Hi,
Please also see this ticket for similar issue: https://theme.co/apex/forum/t/unable-to-turn-off-uppercase-for-nav/35540/2
It seems like footer options - Footer Menu & Footer Social are also not saving. Turn them off - no change on screen (can still see Assign A Menu in footer), Save - refresh - Options are enabled again?
Please see ticket linked above for login details to the site.
Thanks
Mark