Hi Dmitriy,
This is exactly what I expected. It would help, though, if the YSR logging could have been set to DEBUG. Anyway, the problem must be fully reproducible as the same error has recently been reported from different sources, I beleive.
From what I can see, the service returns an error on second (or consecutive) recognition request in the same gRPC stream. Here is what is happening in more details. After the first recognition request completes, the user application plays a relatively long prompt to the caller. At the same time, the second recognition request is initiated. The caller starts speaking only when the prompt is finished. All is OK, nothing is really extraordinary. However, whenever gRPC config and audio chunk are sent, the service comes back with this the misleading status "Chunks have to be sent with at least one per 5 seconds frequency" in response to first audio chunk in a new utterance. Strange..
Here is the main sequence of events leading to this error condition.
2020-01-20 19:52:40:915828 [INFO] Create gRPC Stream <8b5180abefbc4540@yandexsr>
2020-01-20 19:52:55:380472 [INFO] Speech Detector State Transition NO-INPUT -> IN-PROGRESS [14470 ms] <8b5180abefbc4540>
2020-01-20 19:52:55:380647 [INFO] Received Response: status [0] end-of-utt [0] result-count [0] <8b5180abefbc4540@yandexsr>
I believe the problem shall be addressed by the service provider in the same or a similar way the problem was originally fixed for the first recognition request in a session (gRPC stream).