Thank you for your advice. However, only this code has solved the issue:

@font-face {
  font-family: FivoSans;
  font-style: normal;
  src:
    url("FivoSans-Medium.woff2") format("woff2"),
    url("FivoSans-Medium.woff") format("woff");
}
.fivosans-custom-class {
  font-family: 'FivoSans';
  font-weight: medium;
}

.fivosans-medium-custom-class {
  font-family: 'FivoSans';
  font-weight: medium;
}
.newsfeed .medium {
  font-family: FivoSans;
}

I had to add .medium, and now it works 😊👍 Thank you very much!

Thank you for your advice. However, only this code has solved the issue:

@font-face {
  font-family: FivoSans;
  font-style: normal;
  src:
    url("FivoSans-Medium.woff2") format("woff2"),
    url("FivoSans-Medium.woff") format("woff");
}
.fivosans-custom-class {
  font-family: 'FivoSans';
  font-weight: medium;
}

.fivosans-medium-custom-class {
  font-family: 'FivoSans';
  font-weight: medium;
}
.newsfeed .medium {
  font-family: FivoSans;
}

I had to add .medium, and now it works 😊👍 Thank you very much!

Hi, thank you for your time. However, it hasn’t helped. Maybe there is another problem in my CSS file?

Hi guys,

I would like to inquire you to help me with changing a newsfeed font.
I`ve already done this modification of custom.css:

@font-face {
  font-family: FivoSans;
  font-style: normal;
  font-weight: medium;
  src:
    local("Fivo"),
    url("Fivo/FivoSans-Medium.woff2") format("woff2"),
    url("Fivo/FivoSans-Medium.woff") format("woff");
}
.fivosans-custom-class {
  font-family: 'FivoSans';
  font-weight: medium;
}

.fivosans-medium-custom-class {
  font-family: 'FivoSans';
  font-weight: medium;
}
.newsfeed {
  font-family: FivoSans;
}

body {
}  

The font was converted from TrueType to Woff and Woff2 a I have copied it into this folder:

/home/pi/MagicMirror/fonts/node_modules/roboto-fontface/fonts/Fivo

I am a Newbie in CSS, so if you have any idea what I do wrong, give me an advice, please.