My "Customer List" appears to be in alpha order until I try to print labels or letters. It doesn't make since - help.

The order you see in various features in QB like reports and labels/letters will usually be the lists' "natural" sort order, not the way you've sorts the customer center, which can be sorted on many fields including name.

To see how your customer sort will appear in these features, click the little diamond at the top of the list:

Once you do that, then the top of the list won't show it sorted by name as it does above.

Based on what you're reporting your customers will not appear in alpha order.   This means the underlying list is in "custom" sort order.

To get back to the standard alpha sort order, you'll need to sort your entire names list.

To do this, open a check (weird, I know) and then press Ctrl- L after clicking in the Payee field on the check.  Then find and click the Name button at the bottom of the list and pick Re-Sort List from the menu that appears.