No, the default is wait. You may well see errors that you
did not see previously if you use no_wait.

I did not specify any other patams except concurrency.

Interesting.... V2 has been in alpha and beta for more than 18
months, so if there were an obvious problem we'd probably have
found it. I'm not questioning what you saw, but wondering what
is different....

Sorry to be the bearer of bad news, maybe the developers could take a
closer look.