Page refresh required to see non-lating index letters

Looks like we somehow went to LP:550876, empty buckets are displayed again, but this time a refresh of the page is required to see non-Latin index letters.

There is a default set of A-Z letters which is always visible no matter whether there are contacts for that letter or not. At the same time adding new contact with ASCII name will allow the bucket to be clicked. Adding, say, Cyrillic name (Роман Епишев) will not allow immediate access to the bucket.