Do you get the same issue if you run a similar query via Sage Report Designer?

Technically the ODBC driver is not supported for direct consumption by 3rd party applications I'm afraid, and the ODBC driver only exists to support running and exporting data via Sage Report Designer. Having said that there is no technical barrier stopping you consuming the ODBC driver directly, but if you chose to do so bear in mind that the lack of official support means that you'd be on your own, will be limited by what the ODBC driver currently supports (e.g. it is read only, no guaranteed performance, not all data is exposed to it, does not fully support ANSI SQL or common SQL functions, etc), and if there are issues that only affect 3rd party applications you may have to work around these.

With all that in mind my general advice of things to try/look at would be:

1. Try a similar query in Sage Report Designer instead of Power Query.

2. Try upgrading to a newer version of Sage 50 Accounts.

3. If it is just the date/time columns that you are getting issues with in Power Query then you may be able to simply omit these fields from your queries.

4. Try going via an intermediate data source e.g. use Excel Integrated Reporting to import the data in to Excel, or create a linked table in Access, and then base Power Query on that data rather than consuming.

Hope that helps