We are using TWS 9.73.02.
Thanks for the link on the release notes. Went through the same and there does not seem to be any reference in it to suggest that our issue may be solved in any of the subsequent releases.
We are running the following DDE query every 2 minutes.
=Sjexxx856|hist!'id100?req2?ESM9_FUT_GLOBEX_USD_~/20190318singleSpace9singleColon16singleColon00_3000singleSpaceS_6_TRADES_0_1'
This is set to run every 2 minutes changing the end time highlighted above.
This returns results for about 97...