License reactivate problem again

I have read postings on this issue, and sense that one previous response may put me near a solution… So I will first describe my specific problem:
I have eMclient Pro running on two Windows 10 PCs, which I believed was permitted when I purchased the software. I see eMclient sent me a second activation code 2 weeks after my purchase, which I assume I used to activate the second machine. Current version is 9.2.2157. Both machines have run fine for over a year. Lately I have been getting an error message on both machines that “eMclient doesn’t have a valid license. Reactivate” When this error box appears, I also see that the program has not synced email and calendar for a short while. When I select the “Reactivate” button on the code box, I get a response that the license is good, but no listing of the license number or the activation code, and everything syncs again. I get these error codes every two or three days.

I could try re-inputting the activation codes for both machines, but I don’t know how to do that. There is also reference to changing an email address relating to the individual copy of the software. Don’t know how to try that either. Might I need a new activation code? Or is there another path I could follow? I would appreciate your recommendations.

I have eMclient Pro running on two Windows 10 PCs, which I believed was permitted when I purchased the software. I see eMclient sent me a second activation code 2 weeks after my purchase, which I assume I used to activate the second machine

Did you buy 2 eM Client Pro licenses at the time ?

Also if you did, is each Pro License registered to a different email address or the same address ?

This is because you are activating the same single device license on both computers. If you activate it on a second computer, the first one will automatically lose its license. Then every time you change computers, you need to reactivate the single license again.

However, you have two licenses, and each one is for one computer only. Activate a different license on each computer then you won’t have any problems.

If you have lost your license keys, you can have them resent to you from the Lost Activation Key page.