Hide option not showing on some pages

Hi again,

I’m afraid I’m facing another issue…

The option to hide or show the table of contents is working on most pages, however, on some, it doesn’t appear. The table opens and can’t be hidden. The problem is occurring on pages and posts, but only every now and then. For example, it is not working on either of the following

https://southeastasiabackpacker.com/kalaw-myanmar/ (post)
https://southeastasiabackpacker.com/destinations/indonesia/bali/ (page)

However, it is working fine on this one

https://southeastasiabackpacker.com/erawan-waterfall-kanchanaburi/

Do you know what could be causing this?

The page I need help with: [log in to see the link]