Hello Matthew,
Thank you for the update.
We had issues with excessive dropouts when using the beta2 viewer and 6.10 hosts. However, we have updated our self hosted server to beta2 and that has helped enormously. So currently, our overall configuration is Self Hosted Server 2.9B2, Viewer 6.10.10, Hosts 6.10.10.
Please note that it's not recommended to use Viewer and Host of different versions as the version mismatch might cause performance issues. Of course, we try to maintain as much backward compatibility as possible, but we cannot guarantee that it does not affect connection speed/performance.
With regard to the group policy, although I cannot rule out some sort of specific GP config creating the issue, if this is cause, then it is something we are replicating as we have faced this issue across about 10 different client sites, all with completely independent GP and AD implementations.
I've additionally checked on the issue with our developers and they confirmed that it's caused by some GPO settings. Unfortunately, this is something that you need to refer to your system administrator and ask them to further investigate the issue. Sorry for the inconvenience.
Please let us know if you have other questions.