Hello! I understand you're having trouble connecting to the Sengled Home app on your Mac with OS X 10.15.7. Let's work together to get this sorted out. Could you tell me a bit more about what's happening? For example, do you see an error message when you try to open or use the app? Or does it fail to connect to your Sengled devices?

Meanwhile, here are some initial steps you can try:

1. Check Network Connection: Make sure your Mac is connected to a stable Wi-Fi network. Sengled devices and the app usually require the same network.

2. Update the Sengled Home App: Even though you’re on a Mac, if you’re accessing the app through a browser or a companion app, ensure it is the latest version. Sometimes app updates fix compatibility issues.

3. Restart Your Devices: Close the Sengled app completely. Then restart your Mac and your Sengled hub or devices if you have one.

4. Check for Firmware Updates: If you can get into the app at all, check whether your Sengled devices and hub firmware are updated to the latest versions, as the app sometimes requires this to connect properly.1

5. Router Settings: Sometimes routers block device connections. Confirm the router isn't blocking or blacklisting your Sengled devices by checking your router’s MAC filtering or firewall settings. Sengled Smart Wi-Fi bulbs’ MAC addresses start with “B0” if you want to whitelist them.2

Could you let me know which of these you've already tried, and any other details about the connection problem? This way, I can guide you with more tailored steps.