@petra-pik I am embarrassed to say that I may have solved the issue with your help - thank you!
Whilst I could not see the details of the account I was logged into (on each/either phone) as per my most recent reply, I have made a check, by logging out of both and then logging back in with the Premium-subscribed account details, on both phones. They both now display the Premium subscription, at the same time, and I no longer need to 'restore purchases' and swop between them.
I'm not sure I understand how or why this has happened. I'm guessing that the secondary phone was perhaps using an old login which was not the Premium one. (I'm never prompted to log in when I open Windy). But if this was so, why would the 'restore purchases' process then kick me off the primary phone and require the same procedure in reverse...
Anyway - it's not important that I understand this. It now seems that I am logged into Windy on both phones using the Premium account details, and I can see it on both, at the same time!
Thanks for your methodical checking - and I'm sorry to have been a numpty ;-)

@petra-pik When I click on the 'headshot' icon (which has the word 'Premium' superimposed on it, I see the following options:

• Change my picture
• Change password
• Logout
  This is the same on both phones - but I can't find the details of the account which is presently logged in. Where can I check the account name?! Having clicked *Logout I then sign in again with the same account detail on both phones.

@petra-pik Not to my knowledge, and not intentionally! Is that possible? Would it require two different email registrations?

@petra-pik One phone has Android 9, the other Android 11. Both are running Windy v27.3.1

@petra-pik thanks. Whichever phone I used last time, retains the login and it works continuously. If I want to consult Windy on the other phone then I need to 'restore purchases' -
and this then becomes the 'subscribed device'. Later, I need to repeat the process in the other direction. It's just frustrating, rather than difficult... often the 'wrong' phone is the one I want to use right now!

Hi, I have a Premium subscription. My life requires me to use two phones, separate for work and private use. I have the app installed on both phones, but only one of them can have the 'active' Premium subscription. It's a chore needing to 'restore purchases' every time I need to consult Windy on the 'other' phone. Then next time, switch back again... It takes just a few seconds, but it's a nuisance and a delay I could do without.
Is there any way to register two devices where I can have my Windy Premium information available, please?