@srikanthp689160 Do you see any error in the network tab when you upload the image? A 403 error like? If yes, it could be due to a dispatcher or a firewall block. Since you have already verified dispatcher rules, please look out for firewall rules.
All the domain URLs are usually behind a firewall, which are governed by rules called Web Application Firewall (WAF) rules.
I recommend you to verify these WAF rules and see if the AEM requests for Image upload are being blocked by one of such rule.