Basically, there are a set of units which are "calendar-aware", meaning they understand things like leap seconds, number of days or weeks per month, daylight savings time, etc. These units are singular quantities like 1h, 1d, 1w, 1M, etc.
Then there are "fixed" intervals which are strictly multiples of SI milliseconds. 2m is 1000ms * 60 * 2, etc.
Fixed intervals are not compatible with calendar and vice versa. So what happened is your Rollup job is defined as 60m (fixed time), but the query is asking for 1h (calendar time), and that's where things are going wrong. If you change the query to 60m I think it should work.
This is definitely a very confusing situation, and something that most users don't even know about. We just recently merged a PR to make this distinction explicit with two new fields on the date histogram agg (calendar_interval and fixed_interval), to hopefully clear this confusion up in the future.
Inside Kibana on the visualisation the interval is set to 60m, with the query outputting 1h.
If this is an issue that 7.2.0 kibana will fix. More then happy to wait till then. I have the none rollup version of this visualisation working, just not including the amount of data I was hoping for .
Oh, this is interesting. Might be a bug with how Kibana is generating the queries then. Lemme ping a few folks and direct them to this ticket.
The calendar_interval/fixed_interval fields were introduced in ES in 7.2, but I don't think Kibana will have support for it until 7.3 (I merged it a bit later and I don't think Kibana will have time to implement for 7.2).
Thanks for the detailed help btw! Definitely helps us identify issues easier/faster.