That will not be a problem with this formula but rather a problem with the formula where you collect the different ID's could you share the code Please?
For the set problem this is the solution:
If(
CountRows(collID) = 1,
Patch(
'Tracker',Defaults('Tracker'),
{Title: Concatenate(Replace(strUniqueID,Find("[WDID]",strUniqueID),6,txtWorkdayID.Selected.Value), Text(Int(rowCount)+1)), 'Requested For': LookUp('Masterlist', 'Worker ID' = txtWorkdayID.Selected.Value, Title), 'Requested By':txtReqBy.Value, 'Workday ID': txtWorkdayID.Selected.Value, Item: txtItems.Selected, 'Request Type': txtReqType.Selected,'Specific Request Description':txtReqDesc.Value}
),
CountRows(collID) > 1,
Clear(rowCount);
ForAll(
collID,
Patch(
'Tracker',Defaults('Tracker'),{Title: Concatenate(Replace(strUniqueID,Find("[WDID]",strUniqueID),6,txtWorkdayID.Selected.Value), rowCount), 'Requested By': txtReqBy.Value,'Requested For': LookUp('8982 HK Ops Masterlist', 'Worker ID' = txtWorkdayID.Selected.Value,Title),'Workday ID': txtWorkdayID.Selected.Value,'Request Type':txtReqType.Selected, 'Specific Request Description': txtReqDesc.Value, Item: txtItems.Selected}
);
Collect(rowCount, {Value:CountRows(rowCount) + 1});
)
);