No matter what interval I select for refresh in the Stock Ticker app it continues to only display the stock price at the time I added that ticker to the app.
Is this no longer a forum for getting support for this device?
This one looks to be StockData by ingmarstein. It was one that was available from the start. Has it been superceded?
Actually, the original (native) stock ticker app is no longer available in the store, and ingmarstein’s StockData is a relatively new replacement that’s supposed to behave similarly, but you have to provide your own API Key from StockData.org - API Documentation for it to work. Have you registered on that site and entered your API key in the settings? It won’t work without that.
He actually has added the ability to use a different data source with a more generous API limit (because StockData is limited to 100 requests/day so it’s also possible you might run into that, causing stagnant data), but the PR for that addition of the apistocks.com API has been stuck waiting for approval for over a week 
There’s also the Stonks app by @harrisonpage.
It’s very simple and straight to the point, just displays the stock price… no chart.
Similar to the others above, you need a free subscription to polygon.io to be able to generate and use your own API key.