"is not recognized as an internal or external command, operable program or batch file" despite it being in the PATH Windows 10

Question

I have installed a program called i_view64 and I have added it to the PATH in Windows 10.

If I type in the command i_view64 or i_view64.exe into cmd (within any directory on the computer) the program launches as expected, however, if I do the same thing using Python's OS module through the following command:

os.system('i_view64')

then I get the following error:

'i_view64' is not recognized as an internal or external command,
operable program or batch file.

I have already looked at a few questions already on StackOverflow including this one, however, this does not help me, since I already have i_view64 added to the PATH and it works when instantiated through cmd just not through the Python OS module.