How to use CiviCRM contact data latitude and longitude in drupal gmap formatted view Environment
Drupal 7.67
civicrm 7.x-5.13.4
GMap Module 7.x-2.11
Location 7.x-3.7
Views 7.x-3.23

What is working
I have CiviCRM contact data for organisations which has been successfully geocoded using google
I have view in Drupal that can access and display this contact data in a table including company names and latitude and longitude
I can display a google map in the contact record in CiviCRM, so I know the Lat &amp; Long is correct

Problem
When I change from a table to a gmap format in the view no map is displayed, 

View setup


  Format Format:GMap | Settings Show:Fields | Settings open Add Fields
  CiviCRM Website: Website URL (Website) CiviCRM Contacts: Contact ID
  CiviCRM Contacts: Organization Name (Retailer) CiviCRM Address: Full
  Street Address (Address) CiviCRM Address: Postal Code (Postcode)
  CiviCRM Phone Details: Phone (Phone) CiviCRM Tags: Name (Name) CiviCRM
  Custom: Organisation Fields: LALG Member Benefits (LALG Member
  Benefits) CiviCRM Address: Latitude (Latitude) CiviCRM Address:
  Longitude (Longitude)


GMap format settings


  Grouping field Nr.1
  
  You may optionally specify a field by which to group the records.
  Leave blank to not group. Macro [gmap ] Enter a macro. If left
  unchanged, it takes the default settings from
  /admin/config/services/gmap. See the documentation on GMap macros.
  Data Source
  
  Latitude field -> Latitude
  
  Format must be degrees decimal. Longitude field -> Longitude
  
  Format must be degrees decimal. Marker handling


I am also log messages when executing the view:


  php   Fri 7 Jun - 10:43am Notice: Array to string conversion in strtr()
  (line...  gjw
  php   Fri 7 Jun - 10:43am Notice: Array to string conversion in strtr()
  (line...  gjw
  php   Fri 7 Jun - 10:43am Notice: Array to string conversion in strtr() 
  line...   gjw
  php   Fri 7 Jun -> 10:43am Notice: Array to string conversion in strtr() 
  (line...  gjw


Details


  Type  php Date    Friday, 7 June 2019 - 10:43am User  gjw
  Location https://ref.lalg.org.uk/admin/structure/views/view/retailers/edit/retailers?destination=retailers
  Referrer  https://ref.lalg.org.uk/retailers Message   Notice: Array to
  string conversion in strtr() (line 1835 of
  /var/sites/r/ref.lalg.org.uk/public_html/includes/bootstrap.inc).
  Severity  notice
There is a good recipe for using leafhttps://civicrm.stackexchange.com/questions/12862/how-to-put-your-civicrm-contacts-on-a-leafleft-map-in-5min if you are happy to slightly switch track. For D7

Also you will get more Civi eyeballs if you post on that channel, and while I appreciate this is a 'drupal' question, more civi folk use drupal than drupal folk use civi ;-). Good luck