I struggled a bit with the post above but I suspect the problem is that the ioHub data store isn’t as flexible as the TrialHandler with adding new data fields. Basically, all the data fields you want to store need to be specified at the createTrialHandlerRecordTable() stage. You can’t add new ones later, as you can with the TrialHandler. i.e. ioHub populates the fields in its table with the initial state of the TrialHandler that gets passed to it. It doesn’t have any way of noticing subsequent changes to keys in the TrialHandler’s list of dictionaries.
To get around the issue, just populate your initial conditions with blank values for a given variable name (i.e. either use a conditions file with a header for a column which contains no values, or if using dictionaries, a key with some null or placeholder value).