Uncaught Error: Can not send postrobot_method. Target window is closed

I have a multi-step checkout that shows the customer a series of steps to go through the checkout process. When they first get to the checkout page, the billing section is showing as the first step. Going forward and backwards in the steps is handled by JavaScript. When the customer fills out their billing information, WooCommerce sends an AJAX request to the server, and that triggers the following error shown in the console:

Uncaught Error: Can not send postrobot_method. Target window is closed

This error causes my reCaptcha v2 to stop working, so nobody can checkout, and so we obviously can’t use this plugin as-is.

If I reload the checkout page this doesn’t happen, but we can’t expect the customer to know to do this. If I clear all the cookies and other storage, I get this error every time on the first page load. I’m just trying to provide as much information as possible.

Other Paypal plugins haven’t had this problem, but I’m switching to Braintree so trying out your plugin. I hope you can fix this issue!