Hi ocorbo, welcome to Thunkable! 
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As for your question, there are a few areas that need to be corrected.
You have “set app variable app variable BluetoohDevicesNameList” after your scan. There is a dedicated “set variable” block you should use instead. You might have to click on the dropdown and select the variable you want to set.
You need loop through the app variable BluetoothDevicesNameList and if “j” contains “pdstal”, then you do what you need to with “j” as it contains the name you are looking for.