alsaaudio will need to wait for the audio engine service to kick in. It may be that you’re loading the python script before alsaaudio is done booting. 
Is it possible to add a 60 second delay in your Systemd file?
Alternatively I found the method I used for my Parisians project to be 100% reliable so far 
Feel free to copy that.
Here is a link to the github where I go into detail.
