Why am I getting PermissionError [Errno 13] when attempting to write to log in Flask hosted by Apache?

I am running Flask 1.1.4 via Python 3.5.3, hosted via an Apache 2 server on Debian Stretch. I am attempting to log various messages from the program, using the python logging module. This works normally. However, if I restart the Apache server using sudo service apache2 restart, the Flask application errors out with PermissionError: [Errno 13] Permission denied: (log file name). Is this an issue anyone else has run into?

Answer

It turns out that there was a cron process that was editing the ownership of all files in my log folder to root. Once the program was restarted and needed to re-obtain the file reference, it was unable to do so.