Toggle Content no longer functions

Good morning,
Toggle Content no longer functions, other than standard updates no other changes have happened – no additional plugins have been added, etc. Yet the toggle does not function.
Looking at what’s happening, it appears to be putting a “display:none” style inline, but for the life of me I can’t see where that instruction is coming from. I’ve looked at the shortcode creation and all the CSS, inspecting the item tells me that the style is coming from inline commands.
I can’t send you my login info, the website is still on a private intranet before going live next month. Can you direct me on where I can find the offending code and remove it please?

Thanks