False alert database file is running low out of space

Here is part of the email i'm getting 'The database file"xxxxxxxxxxx" is running low on space 5. But when I look at the available disk space its not less than 5%. This alert is set to go off every 1 minute until the situation changes but still it randomly fires out once during the day and sometimes twice like we made some changes to the available space which is not the case. I have seen almost similar post from here and not exactly what I'm looking for. Could it be the perfmon counter that checks database space volume is looking at the available autogrowth space? and yes my disk is also local. why does it not keeping alerting us every minute if at all the alert was true? How can I fix this without disabling the alert and I also think it has nothing to do with the threshold 5%. Please I need your input on this. Thanks