I read and checked that the "My Domains" of production orgs and sandboxes are managed separetely, which means that a specific domain can be available on a sandbox for a specific POD (ie. cs81) and not available in production or in another POD and vice-versa.
So I try to figure out how Salesforce ensures that when I will refresh or create a sandbox from my production which has a "My Domain" that this domain is not already registered by another customer on an sandbox with the same name on the same POD ?
Do they search an available POD without my production domain already registerd (with my sandbox name) in the sandbox creation process ?
I also noticed that the domain registered for a sandbox is used in the Lightning URL without mentioning POD:
Is there a risk of conflicts if 2 sandboxes use the same "mydomain" and "sandbox name" on 2 different PODs ?
Thank you for your answers.