UTM 9.5 problem after change to NAT on Cisco ASA

I have a problem with our HA-Cluster.
   Both external interfaces work with Uplink Balancing.
   We change the second Interface (ASA) from directly connect to NAT.
   Now the Uplink monitoring switch the ASA port to offline. I change from automatic monitoring to dedicated host and the port come up.
   I test with the support tools and found that i can't do a Traceroute over the ASA port the DSL Port is ok.
   Now i search into the Logs and found many errors into the DNS log.
     
                                          external                                                                   Internal
                           gateway                   IP 
   Normal DSL 192.168.10.10------192.168.10.11/29----- asg2 (2Node HA)---192.168.99.18/28--VLAN to Internal Router
                                                                                   | (Webfilter)
   Cisco ASA  192.168.200.33-----192.168.200.35/29-----|                
   NAT to external
   static IP
   
  Any hints or tips?

Regards