LTM networking issue:

yes, that was what I was suspecting. Commonly, this happens when SNAT automap is not checked. So, I am reading back to your original question. Initially, it looks like you did not have SNAT. Then you enable SNAT automap on the wildcard VIP, and it still did not work. Question, do you have another VIP pointing to a specific service (e.g port 80 or 443)? If you do, F5 matches to the more specific service VIP. As such, you need to check on that VIP to make sure SNAT automap is enabled.

Also, if you have the capture between the src host and dst host, do post it here so I can get a better idea on what's happening.