If the repo mirroring tags are configured as

"latest,3.1,3.2" will work
"latest,3.1, 3.2" will not work because the tag " 3.2" could not be found, since there is a white space between the tags.

While configuring tags fore repo mirroring we do mention "Comma-separated list of tag patterns to synchronize." However dont mention anything about whitespaces, We can either trim the whitespaces or update the description while configuring tags to include whitespaces