Grace period
After an ENS name expires it enters into what's called a Grace period. This is a 90-day window provided as a courtesy where the owner can renew it and keep it at the regular renewal cost.
⚠️ If you let the grace period run out you will lose the name. There are also restrictions on names in grace period. See more: FAQ: What is the grace period?
Keep in mind that the renewal period must be from when the name expired, otherwise the grace period will just be moved up.
For example, if a name expired 60 days ago, and you only extend the registration for 30 days, then the name will still be expired, and the end of the grace period will just be extended for 30 days.
For more information on how this fits into the lifecycle of an ENS name and an overview of all states an ENS name goes through, please see Name Lifecycle