I am building out my first front end form and the total amount field is not populating. We are running on Joomla 3.8.12 and CiviCRM 5.5.1.
Please help, thank you!
From what I can see, it looks like you're not using a price set - so it's actually a mystery why "Total Amount" appears in the first place. You don't have anything to total! I just confirmed on a test site that I don't normally see "Total Amount" on a contribution page that doesn't require it.
If you could edit your question to display a screenshot of the price configuration for this contribution page, perhaps someone will notice something amiss.