Playing the same game from behind the same router can be tricky. Which Router do you use? Or more specifically, which NAT Type is set in your router? Try to set it to "Full Cone" (if your Router/firmware supports it - there are some that don't) and see if that helps. Check out this link for more information.
If it still doesn't work, then check if you're behind a single router with NAT enabled or a chain of multiple routers with NAT enabled? If it's the latter, try to connect directly to the one that's first in the chain and see if that helps or if that isn't possible, try to set them all to compatible NAT Types.
You could also try different UPNP settings of your router, but setting the correct NAT Type should usually suffice.
That said, be aware that these suggestions may have network security implications.
Thank you very much!
We haven't had any issues with Blizzard games (Heroes of the Storm, Overwatch, World of WarCraft), but looking into the links you provided and more generally searching on the matter, I did find one setting on my router which would be considered generally non-compliant for two gaming devices on the same LAN. I hope to test this after work tonight to see if this makes the desired improvement.
Even if it does though, it seems there may still be a bug here due to the behavior this induces on a party. In short, a typical network drop would allow a party member the option to attempt to rejoin the game (tested this with private lobbies configured explicitly to allow rejoining). However, when this issue occurs, rejoining is not an option and to other party members, the game still reports my status as being in-match (even though inside the match, I am not present and my slot is freed- to the point where if the game is public, others can backfill my slot). It seems like at a minimum this behavior needs to be investigated and improved.
Either way, I will report back on whether the router adjustments made any difference when I can test this.
