Hi again!!! I have tried to install the plugin in another domain with the same Coinpayments keys and everything works perfect. The point is that although the Coinpayments account is the same, the exchanges between wallets consider them as withdrawals. Is it possible to make them work as internal movements?
Additionally, even though using the same CoinPayments account for multiple sites is possible, I would advise against it.
You are unnecessarily creating a single point of failure for all your sites in the unlikely case of a security breach.
Also it is now harder to know if the sum of your user balances matches with the balance totals in your account, so it will be harder for you to use the cold storage feature, which is one of your best protection tools against a hack.
In conclusion, I would recommend that you use different wallets for all your sites.