Cards not showing all data even when filtered, except when in the Editor view

I've reached out to support on this already and am awaiting follow up on the issue, but until then, I'm not sure what to do.

We use a large (30M+ row, 300+ column) ODBC dataset for the bulk of our reporting, which has worked out well to date. Cards and dashboards would filter and load relatively quickly and show all data without issue.

However, ever since last week (~9/10) these dashboards have been extraordinarily slow to load and filter. Even more worrying is that when cards/pages are filtered, not all data is shown, even though it is there. For example, if a Sales rep wants to filter to accounts they own, the card is only showing some, not all. It just doesn't show on the chart. However, if you apply the same filters within the Editor, everything looks fine. This is only encountered at the user/production level. 

My hunch is that there was some recent Domo release update that is at play here, as this was never a problem in the past. Unfortunately, in current state our dashboards are unusable since they don't show filtered data properly. While we're working to reduce size (overdue anyways), I don't know how much can actually be reduced to have an impact, so any advice/tips are greatly appreciated.