Timestamp Range Not Working vs. Date Format Range Working

Hopefully this makes sense. I have a document with two fields storing the same data, but one is in an epoch_millis timestamp format, and the other is in a readable format. The mapping for these two fields is:

"latest_datetime": { "type": "date", "format": "yyyy-MM-dd HH:mm:ss },
"latest_timestamp": { "type": "date" },

Where the data inserted via JSON response is an already-formatted date, and a numeric epoch_millis timestamp. Some example data in those two fields for a document would be:

"latest_datetime":"2019-09-15 11:19:43",
"latest_timestamp":1568560783,

I'm attempting to do a range query (I've also tried a range filter) using ES datemath on the latest_timestamp field, but the date math always returns zero results. If I were to do the same datemath on the latest_datetime field, it works as expected. Does ES datemath not work on timestamp representations of dates? Or do I need to explicitly declare the format of the date field as "epoch_millis" for the datetime math to work?

The relevant part of the query:

{ "range":{ "latest_timestamp":{ "lte":"now", "gte":"now-60d" } } }

There are a number of different ways to fix this that involve other fields, or doing timestamp math separately, but I'd like to check for certain that this can't be done all in a single query instead. Thank you!

Note that the date format by default contains epoch_millis, which means the date you specified is somewhere near the epoch, and not in 2019...