Honestly, your IPTV Reseller Panel and your payment gateway are rarely in perfect sync. I've seen a 90-second delay cause a customer to click "pay" twice. The gateway charged twice. The panel created one subscription. The second charge had no home. Customer disputed. Reseller lost the dispute plus a fee. One British IPTV operator now waits 5 seconds before telling customers "payment failed." His panel lets him configure that delay. Most panels don't.
What actually works is a panel with idempotency keys—a fancy term for "prevent duplicate charges." Run a British IPTV payment test through your panel. Click submit twice in rapid succession. Does your panel detect the duplicate? One reseller I know tests this on every panel. His current system shows "processing, please wait" and disables the button after first click. That IPTV Reseller Panel reduced his payment disputes by 90%. That said, some panels blame the gateway. "Stripe's problem." No. Your panel should protect you from gateway quirks. If it doesn't, you're the buffer between two systems that don't talk to each other.