I had the same problem last night. I found on Google the tip to clean not only the cache,but also the data of the Play Store. After doing this, the app finally updated.
Could you attempt to force stop the Google Play store and clear the cache?
Hello SamsungQue. I have been having this problem also. I took the phone to ubreak ifix yesterday and they completely reflashed the operating system software (supposedly more in-depth than a factory reset). Once I restored my data, all of the apps updated like they are supposed to. Today the apps are not updating again. I restarted in safe mode, and the apps did update. Does this indicate that an app is causing the issue? The problem seemed to start after the Aug 1st security update. The other issues are the alarm doesn't sync with the Galaxy watch Active 2 anymore, and the notifications in general are not in sync both with where they are coming from and with the watch. Sorry for the long message.
This may be an issue with the app. Try placing your device in safe mode and deleting the app. If doing this resolves the issue, I recommend reaching out to the developer of the app.