Users receive as the mtls certificate a .pfx packet with their callsign ie. Callsign.pfx.
When using multible servers and working longer time with server you usually collect lots of .pfx packets and you cannot differentiate between the different packets.
Changing the naming to include the intance name helps to manage the files and get rid of the old ones easier.
Naming convention should be ie. Callsign_deployment-name.pfx ~ Street3r_canadian-goose.pfx.