SCG: failing to get routing SERVICE UNAVAILABLE 503 initially after first time deployment/restart of SCG

Environemnt
Spring boot: 2.6.4
spring cloud : 2021.0.1
discovery : consul

running in reactive mode.

**Load test **
We deployed upgraded SCG and trying to perform the Load test with 100 users , and initial time after first time deployment/restart of SCG we see below exceptions and users dropping . In dyna we are capturing these . And these are coming after 30s timeout ... seems like spring cloud gateway is not able to get route within 30s of response-time so it is timing out and seeing 5XX service unavailable.

100 % likely failed due to an org.springframework.cloud.gateway.support.NotFoundException 100 % likely failed due to a reactor.core.publisher.FluxOnAssembly$OnAssemblyException 33.3 % likely failed due to a com.ecwid.consul.v1.OperationException 33.3 % likely failed due to failed service calls to consul on port 8500 with HTTP 500 18.2 % likely failed due to an org.springframework.core.env.MissingRequiredPropertiesException 6.06 % likely failed due to a reactor.core.Exceptions$StaticThrowable 6.06 % likely failed due to a reactor.core.Exceptions$StaticRejectedExecutionException

further 2nd load test runs after 10 or 15 mins with same 100 users are not showing these errors...

@spencergibb could you pls help here.

thanks
Karnam

No source file or test is named. Start by reproducing the first post-restart 100-user load test and correlate the 30-second failures with the listed Consul 500 and route-lookup exceptions; done requires a confirmed cause and agreed fix, which the issue does not specify.