Query works when function is not used - mysql

Question

I'm creating a query that get's the total number of customers within a certain distance of each one of our stores using the Haversine Formula.
This formula is fairly big and looks ugly when I use it in a query, so I decided to create a function out of it so that my queries would look cleaner.
The issue is that when I run the query using the function, I get this error: Error Code: 2013. Lost connection to MySQL server during query.
As soon as I use the actual formula instead of the function in my query it runs as expected. Anyone know why this is happening? Is this a time out issue because the query is taking to long to run?
Here is my user created Haversine function:
CREATE DEFINER=`MYADMIN`#`%` FUNCTION `Haversine`(lat1 DECIMAL(15,10), lng1 DECIMAL(15,10), lat2 DECIMAL(15,10), lng2 DECIMAL(15,10)) RETURNS decimal(11,2)
BEGIN
RETURN (3959 * acos( cos( radians(lat1) ) * cos( radians( lat2 ) ) * cos( radians( lng2 ) - radians(lng1) ) + sin( radians(lat1) ) * sin(radians(lat2)) ));
END
This query causes the lost connection error:
SELECT s.StoreID
, count(c.PBID) as customers
, sum(c.Status = 'null') as 'Not Active'
, sum(c.Status = 'Left Message') as 'Left Message'
from console.Stores s
cross
join console.Customers c
where console.Haversine(s.Latitude,s.Longitude,c.Lat,c.Lng) <= 5
and c.DNC = '0'
and c.Status != 'Do Not Call'
group
by s.StoreID;
This is the same query without the function which runs as expected:
SELECT s.StoreID, count(c.PBID) as customers, sum(c.Status = 'null') as 'Not Active', sum(c.Status = 'Left Message') as 'Left Message' from console.Stores s cross join console.Customers c where (3959 * acos( cos( radians(s.Latitude) ) * cos( radians( c.Lat ) ) * cos( radians( c.Lng ) - radians(s.Longitude) ) + sin( radians(s.Latitude) ) * sin(radians(c.Lat)) ) ) <= 5 and c.DNC = '0' and c.Status != 'Do Not Call' group by s.StoreID;