13.17 body battery vanished?

This is now the second time I've seen this bug. During a normal day, the graph for body battery goes blank. All the data is visible in GC, but the histogram on the watch is gone except for some recent points. The first time this happened I rebooted the watch, manual synced, and it came back but this time that's not working. Actually this time I rebooted and more of the graph points disappeared. See my photo.

Edit: I just synced my Edge 840 and then the histogram reappeared... Maybe this is a Trueup issue since that recently got changed this version??

"Improvements to the Body Battery accuracy when users have multiple devices."