why my app icon display white background？ but the other icon is work well

[brightAI2021]

I set up two icos file in setup.py file, Detail as below code fragment

executables = [Executable("schedule_job.py",icon="pdf.ico", base=base, target_name="to-pdf"),
Executable("start.py",icon="app.ico", base=base, target_name="e-signature") ]

setup(
name="e-signature",
version="0.2",
description="e-signautre v0.2",
options={
"build_exe": build_exe_options,
},
executables=executables,
)

my question is why the icon display white background? After I finishend the build job on my windows PC, One ico displays normal with schedule_job.py,But the other one dispaly white background,when I run the application the icon is still white background,so I replace the icon with the normal icon,but it still not work well .

[marcelotduarte]

I think the problem may have to do with transparency.
Every icon in the executable follows the windows standards, so read this document:
https://docs.microsoft.com/en-us/windows/win32/uxguide/vis-icons