Hi Luke, we'd like to help. Does this happen across devices? Also, is it the same for all analytic reports? Let us know and we'll take a look!
Appreciate the info. To help the right team better investigate, can you send a feedback report from the device/account having the issue: https://goo.gl/WdI0BK . You may not receive an individual response, but the details will help us identify and fix any issues, thanks!