Hi there! I see you're getting a "device timed out" error in the SolisCloud app on your Mac running OS X 10.15.7. Let's get to the bottom of this together.

To start, when you see "device timed out," it usually means your Solis device (like the inverter or datalogger) isn't communicating properly with the SolisCloud server or app. Could you tell me a bit more about when exactly this message appears? For example:
- Is it right after you open the app or when you try to view device status?
- Are you connected via Wi-Fi or Ethernet?
- Have you made any recent changes to your network, router, or Solis hardware?

In the meantime, here’s a step-by-step approach you can try:

1. Check your internet connection: Ensure your Mac is online and connected to a stable network. A shaky connection can cause timeouts.

2. Restart your Solis device and router: Power-cycle (turn off, wait 30 seconds, turn back on) your inverter/datalogger and your Wi-Fi router. Sometimes that refreshes connections.

3. Verify Solis device's network connection: The device must be connected to your home network correctly. If it's connected via Wi-Fi, ensure the signal strength is good and Wi-Fi credentials haven't changed.

4. Update the SolisCloud app: Ensure you have the latest version of the app installed on your Mac. An outdated app could cause syncing issues.

5. Check for firmware updates: Occasionally, the inverter or datalogger firmware may require an update to fix communication glitches.

6. Login and sync again: Log out of the SolisCloud app and log back in. This can refresh authentication tokens and connections.

If you've already done any of these, please let me know so we can try some deeper troubleshooting, such as checking device logs or network settings. Also, if you want, I can pull up some official SolisCloud troubleshooting resources to guide you more specifically.

How does that sound? Are you ready to try these first steps, or have you tried some already?