[BUG] Sandbox subscription create checkout session - Error 400

[simplydevoted]

PayPal Sandbox environment has a serious bug. I was using the default personal and business accounts and my product plans are in USD. Whenever I'd try to subscribe, it would throw this error:

We're sorry
Things don't appear to be working at the moment.

This error would always appear after clicking subscribe button and then entering the login credentials.

I checked the network requests and it was failing on this API endpoint: 

POST https://www.sandbox.paypal.com/webapps/hermes/api/checkout/xxxxxxxxxxxxxx/session/create 400 (Bad Request)

I spent a lot of time fixing this but couldn't. In the end, I decided to create one more sandbox personal account with the country set to United States of America and voila, it worked!

So it seems PayPal Sandbox has a bug where IN accounts don't seem to work at all with USD plans.