Hi @odyssey3080,
Thanks for getting back to us.
As indicated by @imaginedd It is highly likely that the API is not able to locate the field value to the following reasons.
1. The location settings – Kindly ensure that the location settings allow the field to be accessed from there.
2. Ensure that the global post ID is correct.
You could try to do var_dump of the field see how it goes.
Let me know if it helps.
