Help with font changes

Hi,  I have a site where I am trying to change the headings to a custom font. 

Strangely although my custom CSS works across all headings. There are some blocks where the title/heading appears to be not affected by the heading CSS change, and to further annoyance doesn't appear to be related to anything with the paragraph styling either.  It is driving me nuts..

Any ideas?? 

See attached screenshots:

My current CSS is 

@font-face {
    font-family: 'Marr Sans';
    src: url(https://static1.squarespace.com/static/66878d7f61c0fa2fc7fdba9c/t/668910ed39b73f5402412a7e/1720258797685/MarrSansCondensed-Semibold-Trial.otf);}/* General heading styles */
h1, h2, h3, h4, h5, h6 {
    font-family: 'Marr Sans' !important;}

/* Specific classes */
.list-item-content__title {
    font-family: 'Marr Sans' !important;}

.list-section-title[data-section-title] {
    font-family: 'Marr Sans' !important;}

[data-section-title] {
  font-family: 'Marr Sans' !important;}

Please add this css too and it will fix your issue : 

body p, body a {
    font-family: 'Marr Sans' !important;}

Let me know how it goes. 

Thank you! 

That does seem to affect the heading in question, however it also seems to change all the body/paragraph style on the site to 'Marr Sans' heading style. Would you know how to keep this title in 'marr sans' while not affecting all the other the paragraph text?

See attached screenshot