Hello Tony,
Good to see you in Microsoft Community.
The first thing to be clear: to use the "Send tab to your devices" feature, you'll need to sign in your Microsoft account to both target devices, as shown in the image below (you'll see this prompt by using the feature in a Microsoft Edge browser that isn't signed in any Microsoft account).
According to your description, you might have logged in to your current Microsoft account on another device and have not removed the account (or been active for a long time).
Please recall patiently whether you have logged in on another device, and if so, you can log out of your Microsoft account on that device, however, it will take a few days for this setting to take effect.
Or you can visit Microsoft Account | Device to try to delete the device that has logged in to the Microsoft account.
Additionally, I looked up the relevant information and found that others have the same problem as you, you can refer to it. how i can manage the device list in "send page to device" of microsoft edge - Microsoft Q&A
If anything is unclear, please do not hesitate to let me know.
Best Regards,
Mosken_L - MSFT | Microsoft Community Support Specialist