21C Update - Issue with Certificates of Completion in Chrome

Summary

Update 21C seems to have broken Certificates of Completion in Chrome.

Content

With the update to 21C, we are seeing issues with our Certificates of Completion in Google Chrome. It looks like there is some sort of pop-up superimposed on the certificate which can't be clicked to close out (see below). I've included the code for the certificate below. We are not experiencing this issue in Microsoft Edge.

Anyone else seeing anything like this?

Version

21C

Code Snippet

<style>
.clear {
clear:both;
}
#mbi-cert-container {
width: 900px;
height: 616px;
margin: 0px auto;
border-style: solid;
border-width: 0px;
border-color: #00295b;
}
.mbi-cert-sidebar-left {
float: left;
}
.mbi-cert-sidebar-right {
float: right;
width: 5px;
height: 394px;
border-right-style: solid;
border-right-width: 0px;
border-right-color:#00295b;
}
.mbi-cert-year {
color: #00295B;
font-size: 36px;
font-family: Lato, sans-serif;
padding: 55px 10px 0px 0px;
text-align: center;
}
.mbi-cert-static-text {
color: #00295B;
text-align: center;
font-family: Lato, sans-serif;
font-size: 26px;
}
.mbi-cert-static-text.success {
margin-top: 10px;
}
.mbi-cert-static-text.credits {
color: #00295B;
text-align: center;
font-family: Lato, sans-serif !important;
font-size: 18px !important;
}
.mbi-cert-date-region {
float: left;
width: 300px;
text-align: center;
margin: 16px 0px 0px 20px;
}
.mbi-cert-date-region p {
padding-top: 5px;
font-family: Lato, sans-serif;
font-size: 12px;
border-top: solid 1px #333;
}
.mbi-cert-signature-region {
float: right;
width: 300px;
text-align: center;
margin: 5px 20px 0px 0px;
}
.mbi-cert-signature-region p {
margin: 0px;
padding-top: 5px;
font-family: Lato, sans-serif;
font-size: 12px;
border-top: solid 1px #333;
}
.mbi-cert-credits-region {
margin-top: 5px;
text-align: center;
}
.mbi-cert-credits-info {
text-align: center;
font-family: Lato, sans-serif;
font-size: 10px;
}
.mbi-cert-provider-region {
margin-top: 15px;
text-align: center;
}
.mbi-cert-provider-info {
text-align: center;
font-family: Lato, san-serif;
font-size: 12px;
font-style: italic;
margin: 5px 0px;
}
</style>
<div id="mbi-cert-container">
<div class="mbi-cert-header"><img