Urgent help Please !! New to Greengrass and have a few important queries

I already created post yesterday but I believe it is not visible hence asking again. We are on track to upgarde to GG V2 but before that we need to document the below cause. Your help will be highly appreciated.

Have faced the following 3 issues in the past few weeks

-->> My colleague stated that his deployment fails with error stating “Group definition is not valid”? I couldn't find anything in the GG troubleshooting document about the error.

-->> I updated my group definition and added Lambdas to it but I don’t see that reflected on the device. Do the changes take place upon rebooting device ? is the deployment failed ? or the change made on cloud but never made to the device.

-->> In the beginning I couldn't find error logs in my Green grass local machine, neither CloudWatch

Thanks Community, looking forward to exploring GG.

Joan.