REN command with wildcard

I have a batch file, that has been working properly, which renames files in bulk. Example input:

C:\Test\NW\Residents_20190624135727.csv
C:\Test\NE\Residents_20190624135727.csv

The batch file being executed has:

ren C:\Test\NW\Residents_*.csv NorthWest_*.txt
ren C:\Test\NE\Residents_*.csv NorthEast_*.txt

and the output, as expected:

NorthWest_20190624135727.txt
NorthEast_20190624135727.txt

Where it doesn't seem to work is when I have an input file:

C:\Test\CAN\Residents_20190624135727.csv

and use the same command:

ren C:\Test\CAN\Residents_*.csv Canada_*.txt

the output is:

Canada_ts_20190624135727.txt

while I would expect the output to be:

Canada_20190624135727.txt

In my searching online, I haven't been able to find an explanation to this particular problem. After trying variations of input file names and commands, I believe it has something to do with the length of the file names. Can someone explain why this is happening?