Yes there is a known limitation where the reads have to be named a certain way. It's in the documentation too:
Note that in this solution, the FASTQ files need to be named in the following manner:
_R1.fastq.gz
_R2.fastq.gz
This can be updated to your needs by updating the Python regex in start_workflow_lambda.py
You can also use example FASTQs provided here to test:
s3://aws-genomics-static-us-east-1/omics-e2e/test_fastqs/NA1287820K_R1.fastq.gz
s3://aws-genomics-static-us-east-1/omics-e2e/test_fastqs/NA1287820K_R2.fastq.gz
Input S3 bucket (s3://bucket-name/inputs/)
In this case, it looks not work normally.