I had the same problem and it appears to be fixed now. There was a change implemented in iDigi 2.3, which was deployed on developer.idigi.com a couple days ago. This change will convert time to UTC rather than US central time, when using idigi-db (and possibly some custom presentations) to upload your sensor data. It fixed my problem for sure!
Here is the entry from the iDigi 2.3 Release Notes:
Timestamp Normalization Behavior Change:
In previous versions, record timestamps that did not explicitly specify UTC (or an offset from UTC) in ISO 8601 format were normalized to UTC assuming they were US Central Time (with DST offset per US standards). They will now be normalized assuming they are in UTC time to provide a more consistent and global standard.
Smart Energy applications, and other applications that specified the absolute time reference in supported formats will NOT be affected by this change. Also, records uploaded with unreadable timestamps, or obviously incorrect timestamps (such as those far in the past), are likely NOT affected by this change as these timestamps are ignored and records are timestamped with the time of posting to iDigi in UTC.
Those using the production, unmodified, idigi-db Dia presentation, or any other application that provides a timestamp readable by iDigi, but does not explicitly specify UTC (or the offset from UTC), WILL almost certainly be affected by this behavior change.
Examples of supported timestamp formats:
In summary, if you are not already adjusting for the previous behavior in your application, you will not likely be affected by this change. We expect those affected will be a relatively small minority.