Puerto Rico is defined in Phone numbers page (for claiming new phone numbers) as +1939 and it's not possible to search of claim numbers with original Puerto Rico area code (787).
When selecting Toll Free (1939 appears) this issue also occurs.
- 8x8 Admin Console
- Phone Numbers
Apply a Contains or Ends with a filter instead of Starts with. Alternatively, select Puerto Rica as a State.
If you don't apply any Starts with filter, you can successfully retrieve the Puerto Rico number.