Remaining and Estimate values blank/not calculated in agile Scrum board

Summary: Totals for "Remaining" and "Estimate" times are not displaying in the following places in an agile board (scrum):

• Beneath the sprint, to the right of "28 of 51 issues visible".
• "Summary of assigned work"/"Workload by assignee" pop-up dialog, in the "Original time estimate" column.

Steps to reproduce:

• Set up board with following config under "Estimation" tab:
  • Estimation statistic: Orignal Time Estimate
  • Time Tracking: Remaining Estimate and Time Spent
• Add issues with time estimates to this board
• Create a sprint with one or more of these issues

Expected Outcome: Totals for time remaining (beneath sprint) and original estimate (workload by assignee pop-up) should be displayed.

Actual Outcome: Totals do not display (as per screenshots).

Additional Info:
JIRA Cloud
Chrome 47 + Firefox
Worked fine several days ago—no settings/config have changed since that I am aware of.

Please let me know if you require any further info.
Thanks.