Text under footer problem

Howdy, I would appreciate some help with my site.

I’ve found out that some (but not all) text passages and buttons (sic!) (from a sub-page somehow appears under footer on every page on my site. I must have messed something up, but no clue when and what (as I sometimes edit the Mesmerize theme in theme editor, but some time passed since I last did it and only saw this error few days ago). I have absolutely no clue what seems to be the problem.

Website:

https://kociehospicjum.pl/

Screenshot of the area under the footer:

View post on imgur.com

Sub-page the text/buttons can be found on originally:

https://kociehospicjum.pl/allegro/

Any hints highly appreciated.

Thanks!

Mac

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