This is even with the latest version of the plugin installed (1.2.0)
The class that is extended by the WC_TP_Gateway class (defined in trust-payments-gateway-3ds2/classes/class-wc-tp-gateway.php), i.e. WC_Gateway_Cheque (found in woocommerce/includes/gateways/cheque/class-wc-gateway-cheque.php), returns an array with two parameters within the process_payment function (which is also defined in WC_TP_Gateway), one of which is called result and is set to success.
WooCommerce does not receive anything from the process_payment function defined in the WC_TP_Gateway class, therefore it has no way of knowing whether or not the transaction was successful.
“This plugin has been closed as of April 5, 2022 and is not available for download. This closure is temporary, pending a full review” it looks like they’re having issues with the developers/code.
I’ve left trust payments because of the issues, which is a shame, because when the plugin worked, the service was really good and I liked working with their platform.
Meantime I’ve gone to Sellxed and Zion payments. The Sellxed plugin is excellent and much more fully featured, but I’d be happy to go back to Trust if they ever sorted it out.
The latest version of the plugin, 1.2.5, still does not resolve this issue.