In a Magento 2.3.1 site, I have two third-party payment methods and PayPal Express Checkout enabled. On the frontend, the three works perfectly. But, when I am trying to create a new order on admin panel, the payment methods are not displayed when I click on Get shipping methods and rates
I tested enabled the method Check / Money Order in my developer environment, and this is displayed correctly:
What could be causing the other three not are displayed?