Yet another Schedule API date issue

We are using CMS 1.8.12 and I have been attempting to schedule a layout via the API and am getting the “Please enter a from date” error. It works correctly in PostMan. I have read other posts that have received this error but none of those have fixed my particular problem.

This is a var_dump of the parameter that I am sending:

array(1) {
[0]=>
string(155) “{“eventTypeId”:1, “campaignId”:17, “displayOrder”:0, “isPriority”:0, “displayGroupIds[]”:[2], “fromDt”:“2019-08-30 00:00:00”, “toDt”:“2019-08-30 23:59:59”}”
}

And if I json_decode this is the var_dump:

JSONobject(stdClass)#22 (7) {
[“eventTypeId”]=>
int(1)
[“campaignId”]=>
int(17)
[“displayOrder”]=>
int(0)
[“isPriority”]=>
int(0)
[“displayGroupIds[]”]=>
array(1) {
[0]=>
int(2)
}
[“fromDt”]=>
string(19) “2019-08-30 00:00:00”
[“toDt”]=>
string(19) “2019-08-30 23:59:59”
}

Here is a screen shot fromPostman that is working:

Hopefully a different set of eyes will see the problem.