Crashes randomly

[wasder]

I can't reproduce it when subsequently invoke requests manually (using BloomRPC), but it reproduces 50/50 when it invokes through my app.
My guess that's something to do with near simultaneously requests from the app.
What additional info can I provide?

debug: [grpc:4545] [2021-04-14T09:27:28.304Z] sending unary-stream rpc
debug: [grpc:4545] [2021-04-14T09:27:28.304Z] send request to mountebank
debug: [grpc:4545] [2021-04-14T09:27:28.304Z] url='http://localhost:4525/imposters/4545/_requests', data='{"request":{"peer":"ipv4:127.0.0.1:58456","path":"/ru.mts.trading.pub.book.building.BookBuildingService/subscribePlaceOrders","value":{"orderIdFilter":"","instrumentFilter":"BOOB_FIXED"},"metadata":{"initial":{"user-agent":"grpc-java-okhttp/1.35.0","zone-offset":"UTC+03:00","authorization":"6a046a79-8e33-4641-9a17-7cad8a38500d"}}}}'
debug: [mb:4525] POST /imposters/4545/_requests
debug: [grpc:4545] using predicate match: [{"and":[{"matches":{"path":"BookBuildingService/subscribePlaceOrders"}}]}]
debug: [grpc:4545] generating response from {"is":{"value":[],"metadata":{"initial":{"authorization":"6a046a79-8e33-4641-9a17-7cad8a38500d"}}}}
debug: [grpc:4545] [2021-04-14T09:27:28.307Z] sending unary-unary rpc
debug: [grpc:4545] [2021-04-14T09:27:28.307Z] send request to mountebank
debug: [grpc:4545] [2021-04-14T09:27:28.307Z] url='http://localhost:4525/imposters/4545/_requests', data='{"request":{"peer":"ipv4:127.0.0.1:58456","path":"/ru.mts.trading.pub.broker_acc_core.BrokerAccountCoreService/GetUserStatus","value":{},"metadata":{"initial":{"user-agent":"grpc-java-okhttp/1.35.0","zone-offset":"UTC+03:00","authorization":"6a046a79-8e33-4641-9a17-7cad8a38500d"}}}}'
debug: [grpc:4545] [2021-04-14T09:27:28.316Z] response.data="{"response":{"value":[],"metadata":{"initial":{"authorization":"6a046a79-8e33-4641-9a17-7cad8a38500d"}}}}"
debug: [mb:4525] POST /imposters/4545/_requests
debug: [grpc:4545] using predicate match: [{"matches":{"path":"BrokerAccountCoreService/GetUserStatus"}}]
debug: [grpc:4545] generating response from {"is":{"value":{"status":7},"metadata":{"initial":{"authorization":"6a046a79-8e33-4641-9a17-7cad8a38500d"}}}}
debug: [http:7777] ::ffff:127.0.0.1:58504 CLOSED
debug: [grpc:4545] [2021-04-14T09:27:28.334Z] response.data="{"response":{"value":{"status":7},"metadata":{"initial":{"authorization":"6a046a79-8e33-4641-9a17-7cad8a38500d"}}}}"
error: [grpc:4545] /Users/Shared/mountebank-grpc/node_modules/grpc/src/server.js:72
call.startBatch(error_batch, function(){});
^

Error: startBatch failed
at handleError (/Users/Shared/mountebank-grpc/node_modules/grpc/src/server.js:72:8)
at ServerUnaryCall.<anonymous> (/Users/Shared/mountebank-grpc/node_modules/grpc/src/server.js:573:5)
at ServerUnaryCall.emit (events.js:314:20)
at /Users/Shared/mountebank-grpc/node_modules/grpc/src/server.js:486:14 {
code: 8
}

error: [grpc:4545] Uh oh! I've crashed! Expect subsequent requests to fail.