Getting on error in unifrac.weighted with subsample

I’m running the unifrac.weighted command - it works great until I specify a subsampling depth.

The command structure I’m using is:
unifrac.weighted(tree=xxx.tre, group=xxxx.groups, distance=column, subsample=xxxx, processors=32)

The logfile notes the following for each of my samples, then ERROR after all samples are removed:
“You have selected a size that is larger than sampleX number of sequences, removing sampleX.”

I’ve checked the group file and confirmed the number of sequences in my samples is greater than the specified subsampling depth (2050).

Is there something I’ve got wrong in the command?

Thanks in advance for any help you can offer!

Could you send your log file and input files to mothur.bugs@gmail.com?