After having this same problem I dove in and found a fix.
on about line 238 or so of HighriseAPI.php there is a line that looks like this
if(!empty($value) && isset($custom_fields[esc_html($key)])) {
If you replace that line with the following, it will now map your custom fields correctly
if(!empty($value) && isset($custom_fields[strtolower(esc_html($key))])) {
The problem is that gravity forms uses heading case “My Field” whereas the highrise API uses all lower case so “My Field” is not equal to “my field” and nothing was being set.
Hope this helps others in the same situation.
Cheers,
Brendan
