Your code is HTML code so this is shown on the first load. If the changed variant, Product Price will be pulled from the js code and there won’t be the HTML you just added.
Option 1: You can reach Prestige theme and they can help you add code
Option 2: Find a developer who specializes in shopify and pitch your needs to them
This is Victor from PageFly - Shopify Page Builder App
For that, you have to check in your Variants select callback function because on variants selection its works based on Js code,
Check in Asset-.theme.js and find “if(variant)”
But in this case, you are adding the compare price by using custom liquid ( which only shows the first time and will not update ). I think that currently, your theme doesn’t have that feature.
You should contact the theme developer to add this logic handle