Title and body font on gallery page don't show

Site URL: https://www.boutique14.co.uk/

Hi, this one's driving me mad.

I followed this guide https://paigebrunton.com/blog/sauarespace-rotating-testimonials to make a rotating customer quotes/testimonials section on my homepage. I am using Foster template, part of Brine family. It worked really well and everything was going great when I initially tested it. Then, as I was tweaking line spacing for gallery body content in Site Styles, suddenly there was a glitch or something and now the text won't show up. I've tried changing all the relevant Site Styles settings, and the section called "Gallery Content" or whatever shows up and the font is set to dark grey, so it's not a white font on white background issue. The gallery slideshow is definitely there, I can tell because click thru links still work, but the text doesn't show. I have raised a ticket with SS, but don't hold out much hope. Has anyone else had problems with title and body text showing up on galleries, and if so how did you fix it?

I've inspected the HTML in browser and it seems font size is set to zero (this is not the case in Site Styles by the way!). This must be SS's way of not showing title and body text in a gallery but keeping it as alt-text I guess.

p.s. you can see attached where the quotes are supposed to show, between the two big, pink markdown quotation marks. Thanks.

Squarespace Customer Service asked me to delete all Custom CSS. I did that and it didn't fix the problem. So having tinkered around in a browser inspect all the elements, I came up with the following and it fixed whatever is going wrong on the back end. Hope it helps others:

.Index-gallery-item-inner h2 {
  font-size: 14px;
  line-height: 24px;
  letter-spacing: 1.5px;
}

.Index-gallery-item-inner p {
  font-size: 12px;
  line-height: 50px;
  letter-spacing: 1.5px;
}