Alternative Option:

Remake the query adding the Payment Amount and any payments/gift fields first to the output fields and then add your other fields.

Note that the query only allows 25 output fields total, so if that is the situation you may need to remove a field to add the Payment Amount field.

Chat with Support and reference this article. 

Provide the name of the Saved Query Configuration in Control> Query
Provide screenshots and a description of what is happening when trying to add the field