Let me start by saying I have not tried a DDVS in stand-in mode so what follows may not be possible to do in your environment.
I am guessing that by 'return META response', you are saying the service image is returning a 404 Not Found response. This makes me wonder what the VSI tried to select on in order to come up with the META response.
The following may or may not help, but I would probably try the following:
- Run only this virtual service so no other activity is on the machine
- Stop VSE
- Remove the vse.log, VS_<serviceName>.log, and if possible vse_matches.log. Note, if Registry is running, there may be a lock on vse_matches.
- Start VSE
- Get ready to submit the stand-in transaction
- Enable DEBUG in logging.properties
- Run the test
- Enable INFO in logging.properties
- Copy the logs to a location where you can independently look at them.
I would focus on any output that describes the steps the service went through to determine that META was the "response".
You might be able to do the same with other services running, but adding debug will create a forest of information which will make it difficult to look for the specific service.