Reviewing the thread:
1 The data is coming in by radio.
2. Several quantities (not all) have one data point all at the same value.
What is the entry in your emonhub.conf for the two relevant sensor nodes? Are they specific, in that each quantity in the message is uniquely defined, or is there a “general” definition like: datacode = h
Is there another transmitter on the same frequency close by that could be generating a message that’s being correctly decoded? (OK, it’s a long shot, but something like a garage door opener or radio doorbell?)
Yes - in general it’s not possible to save the floating-point representation of a decimal number exactly.
It appears in the code for the “wh_accumulator” - which I quoted in this post: How to accumulate watt Hours correctly from an input? - #12 by Robert.Wall
Also: Emoncms stable release v11.3.0
though neither source explains much. I’m sure I’ve seen it documented or mentioned somewhere else, but can’t find it. I’ve a sneaking suspicion it relates to what happens to missing values, i.e. if there’s a gap (according to the timebase) between the last value in the Feed and the value being submitted.