If you want to disable the auto-reimbursement feature:
Login to Tango: https://hsa.tangohealth.com/t/a/login/launch
Once you are in Tango, click on "Set Up" in the blue taskbar at the top of the screen.
In the sub menu, click "Paying Yourself Back."
Under "Automatic Reimbursement" click on "Change Settings." Next, click on the button next to "No, do not transfer funds automatically." After you have clicked "saved," the screen will now show - "Important: You have disabled automatic funds transfers."
This will prevent Tango from automatically initiating the reimbursement process for you. If you do want to reimburse yourself, you would need to do so manually. In the future, just click the "Pay Yourself Back" button to initiate a reimbursement.