Something similar have happened once before that I know of, the Quirkbot was charging very slow and did not work, directly from factory. We plugged it in for more than an hour, and then it was all good again.
In this case our theory as to what happened is that for whatever reason the battery voltage had gotten to a point lower than is should normally be, the charging chip detects this and goes into what is called a preconditioning mode, meaning it's very slowly rebuilding the charge in the battery, which is the best way to fix a LiPo-battery with too low charge.
The battery do have build in protection circuits to prevent it getting too low in normal usage situations. In other words there is no danger in leaving the Quirkbot on for a long time.
We are checking with production about what could have been the problem with the battery.
If anything else is acting strange or you have any other questions, don't hesitate to ask!