I came up with a work around using Arcade, example follows. Note, indicators require a FeatureSet so if you expect nulls create a null feature\ feature set to return,... just in case. And Arcade can be finicky.
var nullFS = FeatureSet('{"fields":[{"alias":"objectid","name":"objectid","type":"esriFieldTypeInteger"},{"alias":"district","name":"district","type":"esriFieldTypeString"},{"alias":"project","name":"project","type":"esriFieldTypeString"},{"alias":"created_date","name":"created_date","type":"esriFieldTypeDate"}],"spatialReference":{"wkid":102100},"geometryType":"esriGeometryPoint","features":[{"geometry":{"x":-13138847.3052,"y":5875138.111400001,"spatialReference":{"wkid":102100}},"attributes":{"objectid":100,"district":"Walla Walla","project":"Temp","created_date":"2122-03-28T12:51:42-07:00"}}]}');
var fsin = FeatureSetByPortalItem(Portal('https://arcportal-ucop-corps.usace.army.mil/s0portal'), '67d897cf19244c5db57507851a3ff804', 0,['district','project','created_date']);
var q = "project_org = 'usace'";
var fs = Filter(fsin,q);
var testDT = (DateAdd(Now(),-2,"hours"));
var testDT24 = (DateAdd(Now(),-24,"hours"));
var objList = Array(0,"");
for (var f in fs){
var fDT = (f.created_date);
if (fDT < testDT){
if (fDT > testDT24){
Push(objList, f.project);
}
}
}
if (Count(objList) > 0){
var oString = "(";
for (var x of objList) {
oString = oString + ("'"+objList[x]+"'");
}
oString = oString + ")";
oString = Replace(oString,"''","','");
var q = "project IN " + oString;
Console(q);
var fssub = Filter(fs,q);
Return fssub;
} else if (Count(objList) == 0) {
Console("returning nullFS");
Return nullFS;
}