Hi, @dbrys
We’re seeing the exact same two problems. For the “date vs timestamp” issue, we also were able to workaround via casting to Timestamp (see here: MongoDB Filtering Bug? (using Dremio 3.0.0, MongoDB 3.6.8))
The second issue is related to a schema guessing bug when you switch from Preview mode (which I guess you use for testing your queries in Dremio UI) to “real” mode, see here: Bug Report: Schema Discovery Problem with nested documents (Dremio 3.0.0 and MongoDB 3.6.8)). Unfortunately, I’m not aware of any workarounds – if you find one, please let me know.
Best, Tim