I didn't know about antivirus software called MalwareBytes and Rogue Killer. It may be the result of those software reacting instead of Windows Defender.
Lovely Composer is developed in Python and includes a Python script as an official add-on sample. The add-on's source code is completely public and harmless, and Lovely Composer does not run external scripts without explicit user interaction. However, such aspects cannot be detected by the mechanical processing of anti-virus software, and will only warn that there is a possibility of suspicious behavior.
It seems that in modern software development, the more convenient and powerful functions are added for users, the more antiviruses are suspected of being abused. This tendency seems to be particularly strong in tools rather than simple games.
Basically, I'm a game developer, so I'm confused due to my lack of experience, but I want to prevent false positives as much as possible. Some of the options are expensive and may not be available with cheaper software. It may be necessary to remove the function once implemented depending on the case. It looks like it will take some trial and error for a while.