Always getting error 50002 on Google Batch with specific Nextflow process

[vaslem]

process betaMerge {
    label 'python'
    label 'biggermem'
    maxRetries 20
    errorStrategy {if (task.attempt == 20 || task.exitStatus == 1 || task.exitStatus == 137) { s = 'ignore' } else {println "Retrying ${task.name} with more disk size"; s = "retry"}; s}
    disk {
        base = (8.B * csvs*.size().sum())
        mult = task.attempt > 3 ? 3 : task.attempt
        us = mult * base
        println "Disk used by ${task.name}: ${us}"
        us}

input:
    path csvs, arity:'1..*', stageAs: "*/*" //comma separated
    val csv_names
    path samplesheet //tab separated
    val sample_group
    val output_fname // extension should be included
    val large_mem // 1

output:
    path "*.*", includeInputs:false

publishDir "$OUTPUT_ROOT/$sample_group/merged"

shell:
'''
output_fname=!{output_fname}
sample_group=!{sample_group}
large_mem=!{large_mem}
csvs="!{csvs}"
csv_names="!{csv_names}"
csvs_array=( $csvs )
csv_names_array=( $csv_names )
mkdir -p input_csvs
# we need this as the connection with the machine is not to be trusted
cd input_csvs &&
for i in "${!csvs_array[@]}"; do
    csv="${csvs_array[i]}" &&
    fname=`basename ${csv}` &&
    csv_name="${csv_names_array[i]}" &&
    echo "Copying $csv to input_csvs/${csv_name}.$fname .." && {
        ln -sf ../$csv ${csv_name}.${fname} || cp ../$csv input_csvs/${csv_name}.${fname}
    }
done
cd .. &&
args=
if [[ $large_mem -eq 1 ]]
then
    args="$args -l -u 50000"
fi

samplesheet="!{samplesheet}"
if [[ $samplesheet == "undefined" ]]
then
    beta_merge.py -i input_csvs -o $output_fname $args
else
    beta_merge.py -i input_csvs -o $output_fname -s "!{samplesheet}" $args
fi
'''


}

Hi all. The Nextflow process above is supposed to merge multiple CSV beta files into one large file. However it keeps throwing the VM reporting timeout error 50002  . The suggested solution in Google Troubleshoot page ("To resolve this issue, retry the task either by using automated task retries or manually re-running the job.") makes no sense, as I have tried to run the process almost 30 times, getting the exact same error. Has anyone of you observed this problem and how did you mitigate it? Huge thanks in advance!