Thanks for the quick response Tijmen.
I tried both, with just 2.0.4 and then modified wpsl-gmap.min.js. I’ve restored the original so it should be back to standard 2.0.4.
I’ve disabled and cleared the WP Super Cache and the Store Locator transient cache, which had no effect.
I get the same problem on my local site. On that I’ve tried deactivating all other plugins and even changing the theme.
Both site databases use UTF-8 Unicode.
Thanks
James