I think that almost all routers with tailscale experiences this bug. Whenever, there's a shared device on my tailscale account, it will show the email of the one shared the device and not the email of my account.
In this image, it shows the email of the account of the sharer. Also my own email that I used with tailscale uses Gmail as provider. Not much of a problem by the way, but I just let you guys know.