BIG IP does not pass RESET packets

Hello everyone, we have in our infrastructure a fortinet waf behind the big-ip. The WAF is in offline mode, when it detects an attack sends a RESET to the client and the server, making captures we see that the BIG-iP does not pass that RESET to the client. Why does not that RESET pass to the client and pass an END? In the first image, you can see the waf RESET captured. In the second image, you can see interface internal BIG-IP ,the reset packet is. In the third image , you can see interface external BIG-IP, the reset packet is not.