Slider images not showing on Firefox

I accessed my site through Firefox and realizes that the Images on the slider are not showing:

Although, on Chrome they appear normally:

Is it a Firefox issue or an error on my part?

My site has some CSS as following:

/*
  * Overlay no header */
.slide-item::after {
    content: '';
    position: absolute;
    width: 100%;
    height: 100%;
    top: 0;
    left: 0;
    background-color: rgba(0, 0, 0, 0.35);
}

/*
* Retira do Header da Landing Page */
.page header.entry-header {
  display: none;
}

/*
  * Margem no footer da Home Page */
   .footer-widgets {
     padding: 20px 0;
}
   .footer-widgets.widget-area .widget {
     margin-bottom: 0;
     margin-top: 5%;
}

/*
* Stick Header on Mobile */
#masthead.site-header.fixed {
    position: fixed !important;
}

/* *Retira o espaço em branco acima do footer*/
.page-wrap {
    padding-bottom: 0 !important;
}

.entry-footer {
    display: none !important;
}

.page .page-wrap .content-wrapper {
    padding-bottom: 0 !important;
}

.content-area .hentry {
    padding-bottom: 0 !important;

}

.home .site-footer {
    display: none !important;
}

/* *Aumenta o tamanho do popup do Conheça mais*/
.popmake-conheca-mais-video {
    width: 90%;
}

/*
* Define mudanças somente para o modo Desktop */

@media screen and (min-width: 767px){

/*
  * Fixa menu no topo */
    .col-md-8.col-sm-4.col-xs-12 {
      position: absolute !important;
      top: 50px;
      right: 15px;
}

/*
  * Transparent Header Background - Home Page */
    .page-id-474 header#masthead {
      position: absolute !important;
      background-color: transparent;
}
/*
  * Muda o Size da Logo na Home PAge */
   .page-id-474 .site-logo {
     max-height: 220px;
     filter: invert(100%);
     margin-top: 7%
}

   .site-header.float-header {
     padding: 5px 0;
     background-color: rgba(0,0,0,0.8) !important;
   }

   .float-header .header-wrap .col-md-4 {
     width: 33.33333333% !important;
     text-align: left !important;
   }

   .float-header .header-wrap .col-md-8 {
     width: 66.66666667%;    
   }

   .site-header.float-header { 
     height: 120px;
   } 

   .float-header .header-wrap .col-md-4 {
     height: 120px;
     overflow: hidden;
   }  
  
   .float-header .mainnav {
     margin-top: 5px;
   }

/* *Resize Logo when Scroll Down */
    #masthead.float-header .site-logo {
      max-height: 100px;
      transition: 0.5s;
      margin-bottom: 0;
      margin-top: 0;
}

/* *Adiciona espaçamento no header text*/
   .text-slider .subtitle{
     margin-bottom: 3%;
     margin-top: 7%
}

/* *Adiciona espaçamento no header text*/
   .text-slider .maintitle{
     margin-top: 8%;
}
}

/*
* Resize and Left / Right Logo and Menu when scroll down (Mobile) */

@media only screen and (max-width: 767px){

/* *Resize Logo when Scroll Down */
    #masthead.float-header .site-logo {
      transition: 0.2s;
      float: center !important;
      max-width: 80px;
      height: auto;
      margin-top: -3% !important;
}

/*
  * Transparent Header Background - Home Page */
    header#masthead {
      position: absolute !important;
      background-color: transparent;
}

/*
  * Muda o Size da Logo na Home PAge */
   .page-id-474 .site-logo {
     max-height: 130px;
     filter: invert(100%);
     margin-top: 3%
}

/* *Adiciona espaçamento no header subtitle text*/
   .text-slider .subtitle{
     margin-top: 28%;
     font-size: 130%;
     margin-bottom: 2%;
}

/*
  * Fixa menu no topo / direita */
    .col-md-8.col-sm-4.col-xs-12 {
      position: fixed !important;
      top: 5%;
      left: 40%;
}

   .site-header.float-header {
     background-color: rgba(0,0,0,0.8) !important;
     height: 20%;
   }
}

@media only screen and (max-width: 767px) and (orientation: portrait){
    header#masthead nav#mainnav-mobi {
        left: -20%;
        width: 250px;
    }
}

@media only screen and (max-width: 767px) and (orientation: landscape){
   .site-header.float-header {
     height: 26% !important;
   }
}

THanks for your help

Hello,

I’ve just checked your website in Firefox browser and slide images were there. So is this issue already resolved?

Kind Regards, Roman.

Thank you for your fast answer.
I checked in my Firefox here and it’s not showing, do you think it may be a problem on my browser?
Thanks!

Hello,

…do you think it may be a problem on my browser?

It might be a caching issue, did you try to clear your browser cache?

Kind Regards, Roman.