I am working on a form where I want the user to click on a color scheme. I am using bootstrap and I am using circle font awesome icons to do this. When it is clicked, a new font-awesome icon that is stacked appears. I have noticed that when the page shrinks to a certain point, the one icon that is "clicked" disappears.
I know that it is caused because of the icon being stacked, but I don't understand the root cause of this. What can I do to fix this?
Here is a screenshot of the screen at normal resolution:

Here it is when I shrink the page:
Here is the code:
<div class="row pb-4">
<div class="col-md-2 offset-md-2 text-center">
<i class="fas fa-circle fa-2x" style="color: #D1504F;" @click="setRed()" v-if=" this.headClass !== 'bc-header-red' "></i>
<i class="fas fa-circle fa-stack-2x" style="color: #D1504F;" v-if=" this.headClass === 'bc-header-red' "></i>
<i class="far fa-circle fa-stack-2x" v-if=" this.headClass === 'bc-header-red' "></i>
</div>
<div class="col-md-2 text-center">
<i class="fas fa-circle fa-2x" style="color: #4FA1D1;" @click="setBlue()" v-if=" this.headClass !== 'bc-header-blue' "></i>
<i class="fas fa-circle fa-stack-2x" style="color: #4FA1D1;" @click="setBlue()" v-if=" this.headClass === 'bc-header-blue' "></i>
<i class="far fa-circle fa-stack-2x" v-if=" this.headClass === 'bc-header-blue' "></i>
</div>
<div class="col-md-2 text-center">
<i class="fas fa-circle fa-2x" style="color: #4FD17C;" @click="setGreen()" v-if=" this.headClass !== 'bc-header-green' "></i>
<i class="fas fa-circle fa-stack-2x" style="color: #4FD17C;" @click="setGreen()" v-if=" this.headClass === 'bc-header-green' "></i>
<i class="far fa-circle fa-stack-2x" v-if=" this.headClass === 'bc-header-green' "></i>
</div>
<div class="col-md-2 text-center">
<i class="fas fa-circle fa-2x" style="color: #FFCD2B;" @click="setYellow()" v-if=" this.headClass !== 'bc-header-yellow' "></i>
<i class="fas fa-circle fa-stack-2x" style="color: #FFCD2B;" @click="setYellow()" v-if=" this.headClass === 'bc-header-yellow' "></i>
<i class="far fa-circle fa-stack-2x" v-if=" this.headClass === 'bc-header-yellow' "></i>
</div>
</div>