HESTER template - no + button for adding more elements into additional product info

Hi peeps, 

I've been using Squarespace for a few years now, so I am quite familiar with options.
So, I am building new site on the "Hester" template, 7.1. squarespace. From what I can see, it's quite limited comapred to Brine family and 7.0, but anyways, I like some dummy options, and also I think it works quite good as mobile version, without any code tweaks that gave me headaches on 7.0.

Anyways, the problem is - Inside the products, when I want to create additional info, which I used before a lot on 7.0 version for creating complete product pages by adding photos, videos, texts, and so on, on 7.1. + button for adding element is gone. I can't find it anywhere. On earlier version it was in the bottom right corner. 





while on 7.1. there isn't. I tried on hoover, but it's not there. 



I am using Chrome on Version 112.0. on macOS Ventura 13.3.1.

Can you help? 
Thanks in advance!

Update. The same happend with Klipsan theme. When I first opened the new theme, first I went to check is the feature available and I could see it normally. Tried, and it worked. 

When started to change the theme, suddenly, the plus button is AGAIN GONE in additional info. 

Hoooow is this even possible? Am I missing something?