Hi there! I understand you’re having trouble with the Tandem app on your MacBook running OS X 10.15.7 — you can’t write messages, see other profiles, and there are no chats showing up, right? Let me help you get to the bottom of this.

To start, can you tell me if this issue happens only on your laptop, or is the app working fine on other devices like your phone? Also, are you accessing Tandem through the app or a web browser on your laptop?

While I wait for those details, here are some initial quick checks:

1. Check your internet connection — make sure you’re connected and it’s stable.
2. Restart the app — quit Tandem completely and reopen it.
3. Log out and log back in — this can refresh your session and fix connection glitches.
4. App update — verify if the app is updated to the latest version compatible with your OS.

If you’re using the browser version, try refreshing or clearing the browser cache. Also, trying a different browser like Chrome, Firefox, or Safari could help rule out browser issues.

If those steps don’t fix it, I recommend next:

- Checking if your account is properly logged in without any restrictions.
- Ensuring no firewall or VPN is blocking Tandem’s connection.
- Confirming that Tandem’s servers aren’t experiencing outages (usually info is on their status pages or social media).

Please let me know what you've already tried or observed, and we can go deeper from there! Are you comfortable with these steps?