Amazon Chime SDK Live Transcription stopped working

I've followed below link to setup the Amazon Chime SDK Live Transcription

https://docs.aws.amazon.com/chime-sdk/latest/ag/using-service-linked-roles-transcription.html#create-service-linked-role-transcription

I've a Lambda which starts transcription for that I've followed below link.

Start Transcription

To receive transcriptions followed below and implemented the same

Receive Transcriptions

And it all worked well.

But since last few days it stopped working.

But the same code base is working as expected in a different account.

Checked lambda logs which enable meeting transcription and no errors. But in the front end no transcription data is getting recevied.

How I can debug and find out the root cause of the issue and get it fixed.