When looking for a downloaded file it replaces "_" for " " and fails assertion. Is this a bug?

[PedroBonorin0]

I have some tests that download a .zip file and verifies that the file is downloaded. However, sometimes cypress tried to find a file named like "Estimate_A_fName lName_..." (space between fName and lName). The problem is that i have "...fName_lName..." on the spec file(underscore between fName and lName). It happened sometimes, I wasn't able to find a reason for that.
First image is the file it looked for, second one is my code.