Why Are Two Data partitions showing in Disk Utility For Startup Drive

I have a late 2013 iMac 27" running Catalina 10.15.7. I recently had to reformat the startup volume and rebuild it from a Time Machine Back Up. The Current Disk is named "Juntos" it was backed up from a Time Machine backup of a disk named "SpringBoard". When I see "Juntos" in the Disk Utility it shows Volumes named "Juntos", and two volumes both named "Juntos - Data". Those drives are formatted as APFS.

Time machine will not back up the "Juntos" volumes complaining that there are two disks named "Juntos - Data". I temporarily changed the name of one to "Juntos - Data 1" and Time Machine will back them up. Why were/are there two volumes named "Juntos Data"? The Desktop only shows "Juntos" and "Juntos - Data" both before the name change and after. Is this something that needs to be addressed? Is it possible and/or necessary to merge the two Data volumes? I am concerned that if the disk fails my Time Machine backup will be unusable.

Thanks