Failed to activate on my PC

Hello everyone,

I had a problem when I try to activate my PLUS seat on my Macbook and Win10 Desktop.

• Activation on my macbook is OK. I can login as PLUS user everytime I restart unity.
• Activation on my desktop will expire each time I restart the computer. But it shows I've activated two licenses for the seat on my account page.

I've tried to remove all activations and revoke seats. Weirdly my macbook doesn't need to re-activate at all, but my desktop activation always expires after reboot.

Does anyone know how to solve this? Thanks for any help!