WAF Rule

NAT will bypass WAF. If you do not have a NAT rule, the WAF will take over the traffic. If you have an issue, follow Vishals guides with WAF. 

you talk about default NAT or DNAT Rule and for your info when Disable WAF Rule the published URL Working with DNAT Rule and when Disable DNAT Rule the published URL Working slowly  too , I can't understood that will active DNAT or Not 

DNAT is a workaround for WAF. A DNAT will pickup the traffic and directly forward it to the Server. WAF is a reverseproxy and accept the traffic, use it as a proxy and request data back from the server. Different approach. 

DNAT is a workaround for WAF. A DNAT will pickup the traffic and directly forward it to the Server. WAF is a reverseproxy and accept the traffic, use it as a proxy and request data back from the server. Different approach. 

so when WAF and DNAT Rule active the traffic will use DNAT only without WAF Rule ,that's right Sir

Yes. 

But why WAF Rule Logs the traffic whereas all traffic used the DNAT Rule , and how the WAF Rule handling NAT and DNAT and loopback alone , I'm sorry for more quizzes 

See: https://community.sophos.com/sophos-xg-firewall/f/recommended-reads/122357/life-of-a-packet-sophos-firewall

DNAT will pickup traffic before the WAF even considering this traffic. The Traffic will flagged for NAT. 

Hi Walid Fawzy: Once DNAT will match there, it will take precedence and after getting the matching DNAT rule that same traffic will try to get matching Firewall rule ( this firewall rule could be normal Firewall rule which you configured to allow traffic for that DNAT or your WAF rule as well if your configured WAF rule is on top and matching the traffic) but as LuCar Toni mentioned once DNAT will me marked, reverse proxy will not handle that traffic. 

Thank you for your info and if you can tell me your Tips about how handle traffic by WAF Rule when Access the Published URL the traffic is more slowly , where the URL Contains images and Gifs and text .