Only use manual renewal for subscriptions that might be cut.
The Subscription From and Subscription To dates in the POL are intended to apply to the subscription over the whole course of its life at your library, not just the current subscription period. They are NOT supposed to be changed from year to year.
Populate Subscription From with the date you first started subscribing to the title.
Leave the Subscription To date empty if you haven't cut or canceled the serial. If you do cancel a serial, you'd enter the Subscription To date in the POL at this point.
(For renewals, enter the subscription range in the Alma invoice, not in the POL. In the POL, you should only update the price and the renewal date.)
POLs with manual renewal selected automatically close at the end of the subscription period. To use them again, they must be reopened.