I can see that the steps provided above are correct, MNGK.

Imagining myself as a business owner. We don't want to give our customers an idea of how much we charge on the items we sell to them. Let's check out to see why you still see your markups even if you've already disabled the option to show it up. 

When you add a billable expense to an invoice, the markup will show up as another line item on your view. However, it will not show up on the actual invoice that is visible to your customer. Are you still on the Invoice transaction page, or you’re now looking at the previewed or printed invoice?

One possible reason is you could be using a different invoice template. Please be sure to select the one which you’ve disabled the option to show markup on invoices. Click Customize on the Invoice page and select the correct template, as shown in the screenshot.

If you have other observations on your invoice or other transactions, so we can guide you to check what happened.