[atlas] credit differences between probes?

howdy! (long time listener, first time caller...) I have some probes deployed, and for some period of time I was accruing credits at about the same rate per day per probe. Recently (last week or so?) I noticed that I now accrue at one rate for 1 device and a different rate for 2 other devices. The devices have been up for at least the last 24hrs: morrowc-fios 4 days, 5 hours 21.6k morrowc-comcast 1 week, 2 days 65.7k Atlas@deteque-IAD 3 weeks 21.6k (unsure why the fios one bobbled...but it's still be up for ~4days) Is this expected? or maybe I'm just in some wonky space with the accruals anyway?