@Kar81 Let’s back up for a moment. In the screenshots you shared, it’s all from the Android device that is already on the sync chain. Nothing else is there with it. If you were trying to add that phone to an existing, it seems like perhaps you accidentally created an independent chain rather than adding it.
The QR code and Code Word part that you showed is how you would add a second device. So if trying to add your computer THAT IS NOT ALREADY IN A SYNC CHAIN, you would select to Add To Existing and then you’d put in the Sync Chain Code. If you’re doing it from a mobile device, you would scan the QR code you’re seeing.
I could be wrong, but I’m assuming that you’re saying you’re trying to add your phone to an existing chain and thought you’d be able to add the other device to it via that Sync menu. If that’s the case, it’s not how that works. Instead you’d need to access the QR code or Code Words from your primary device (such as your desktop) and then enter that onto your Android. Your Android can’t have an existing Sync Chain if you want to add it to another. So yeah…(Please let me know if I’m not making sense.)