some FontAwesome icons do not look correctly in nativescript-vue

Hello I am developing a mobile app with nativescript-vue, in this application I use FontAwesome 5.3.1 icons with cheatsheet codes, the problem is that some icons are not rendered as they should be.

here I import the styles and fontawesome in the main.js of the app

import {TNSFontIcon, fonticon} from 'nativescript-fonticon';
import Vue from 'nativescript-vue';

 TNSFontIcon.debug = true;
 TNSFontIcon.paths = {
  'fa': './font-awesome.css',
  'ion': './ionicons.css'
 };
 TNSFontIcon.loadCss();
  //vue ya e
 Vue.filter('fonticon', fonticon);

this icon for example is shown

<Label class="section fa" border="1" textWrap="true" width="110" heigth="20" 
                      :text="'\uf155 80.000'" backgroundColor="#fcfcfc"  />

but this for example that is the one in the row debts with red background has a weird symbol

<Label class="section fa" textWrap="true" width="165" heigth="20" 
                :text="'\uf54c Deudas'" backgroundColor="#ff5656" />

the icon that is not displayed correctly is this and it is not the only one there are several more that are not displayed

what could be the problem ?, to install FontAwesome use as an example the official documentation of the page nativescript-vue link