So My smartthings app works fine on 1 watch, but on the other watch I get “something went wrong while opening your location”. and a “Try again” button. Trying again just duplicates the same result. Any guesses why that would be and how to correct. Also, smart things app is totally inaccessible from any of the watch faces, is this a normal problem?
Welcome to the forum 
Can you provide the brand and model of the watch? While I assume you are referring to the Samsung Watch… there are many other brands on the market.
My first suggestion is to uninstall the ST app on the Watch and perform a fresh/clean install of the app to check if that resolves the issue.
if that does not resolve the issue, report back so other Community members who are more familiar with your Watch brand can try to step in to assistance.
You can also reach out directly to Samsung Support.
My mistake. Its an a Samsung, its the app on the apple I watch. and its a Iwatch -4.