Cloudformation EFS stack fails on ALBCert

Hello, I was following the steps mentioned. However while deploying the CloudFormation template for the ECS Stack, the ALBCertificate is indefinitely stuck with status "Pending Validation" and the Cloudformation stack fails with a timeout error. I tried deploying the stack without the ECSStack and the PrivatelinkStack. The deployment was successfull, however in step 17, the datasync task ends with error:

Task failed to access location loc-08aba4e01d52bfceb: x40016: Could not mount subdirectory /images/froms3 on host 10.0.0.111. Please verify that the subdirectory exists and is properly exported in /etc/exports

Any suggestions on how to proceed?