After "place order", redirected to homepage

Hi, I don’t know what is happening now in my site. After installing credit card payment, something went wrong and I don’t know where.
When I put one order, and I click “place order”, just before being resent to credit card payment, I am resent to homepage.

I have tried the same but with wire transfer, and that’s the same, I am redirected to homepage but in this case the customer receives the email for payment.

I am checking everything and I don’t know where I am wrong.

My site is in Spanish; it used to work (at least with tests).

At “checkout page endpoints” I have “order-pay, order-received, add-payment-method”

Please I need to fix this ASAP. That would be very kind of you if you could give me a hand on this.

https://www.ads-software.com/plugins/woocommerce/