I have set up a slider with quebly pro as an element in appearance and set it as a hook before footer. And it works there and on the post it’s working partially because not all colours and elements are set as in element and when I go through posts on a different browser it’s all messed up.
You may need to speak to Quebly author – it looks like their plugin only generetes the front end CSS if the Block is within the post content – they may have a filter that can be applied so it will work outside the content.