Empty footer customizing menu

Hi everyone.
Now I try to create footer menu and I want to make 3 sections in a line. But when I click settings button in a footer edit menu I have nothing to edit. It’s just empty. How can I fix this cause it seems it’s just a wordpress bug, any other menu opens and work properly. THANK YOU ALL FOR HELP! I APPRECIATE IT REALLY MUCH ??

Screenshots:
1. Settings button which I click to edit number of sections.
https://prnt.sc/4USNPaYJIBzT
2. How it shows on my PC.
https://prnt.sc/lQb484P8_DVY
3. How it must be displayed.
https://prnt.sc/5Zma3pheifH3

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