Drop Down Menu Not Passing Values to Workflow/Output

[myastarling]

Apologies if I am posting this twice -- the first round did not seem to go through

I'm trying to set up a few chained apps, the first with a drop down for state, the second with a drop down for city. For some reason, the success with the values from the drop downs being passed to the filter is intermittent (i.e. I set it up once, it doesn't work, delete the drop down and action tool and set them up again and they work, only to have them stop working the next time I open the workflow),

and now I'm having the issue where it seems to be ok and the output is correct according to the Interface Designer's returned values, but nothing in the workflow indicates these values were changed (from looking at the exported file, the browse tool, or the dropdown menu that the results from this workflow are supposed to populate).

So what I am doing is inputting the city and state from an existing data source, looking for valid combinations of state/State FIP, taking the combinations that pass and flatten them so they will work in a drop down menu, and then update a specific string in the filter. I've checked the string that is being replaced, the action type and expression value in the action tool, and I can't see what is wrong. The chained app which has the drop down for city also indicates that the default is being selected. 

I've tried this locally on my machine as well as on the server and have the same problem. 

Would anyone happen to know what is going on? I have attached screenshots of my workflow, and the file without the source data.

Thanks in advance.

[BenMoss · Accepted solution]

I can’t take too long to look at this but my glance over it suggests the problem is that you have tools between your input and the drop down. This should never be the case. Your input should connect directly to the interface tool, preferably through the ‘values from external source’.

If you need to do some prep of the data before it is in the structure required for the drop down menu from an external source (which is two fields, one name and one value), then you need a chained application which although you mention you have used in your post, the configuration does not suggest you have.

There is a good response about why here: https://community.alteryx.com/t5/Data-Preparation-Blending/Update-Dropdown-Selection-from-User-Input...

[myastarling]

This worked perfectly! Thank you!