404 Page not found on check out

Hi.

I have done all the obvious testing disabled plugins etc:

After a customer adds a product to basket and then goes to checkout they select Opayo (Previously Sage Pay) but it takes them to a 404 – Page not found.

Same result if they select”Pay by Phone”

Paypal check out works fine.

I have spent half a day with Woocommerce support online testing the site and Woocommerce have advised its a theme issue.

I have also spent a lot of time with hosting to make sure its not a security issue, we have created a staging copy and this is doing the same.

We are using a child theme and this is when we see then above issue, when we switch to enfold theme then the whole check out page is greyed out and unable to select any payment options.

Currently we can not accept any payments and its our biggest week for Black Friday sales!

The site is well maintained and we have been with.Enfold for overt 6 years!

Please can support have a look and advise on the solution,

You can test it by using an incognito browser and the links below.

Feel free to do testing on the live site as we are a School and desperate to be able to trade again.