Help with a measure: Counting rows.

Hello,

I need some halp with a simple DAX query.

I have a table of facts that contains, amongst other things, a created date column ([credte]), a closed date column ([clomatdte]) and a fee earner code ([solcde])

In addition to the fact table (lgmattrr) I have a date table and a fee earners table (lgsoltrr). On the report page there are slicers to filter the fee earner table and filter the date. The date table is related to [credte] (created date)

In my visual I need to count the rows where there is no closed date (the matter is still open). I need a measure that shows the number of matters opened within the selected date range that have no closed date. This is easy:

Open Matters = 
COUNTROWS(
    FILTER(
        lgmattrr,
         ISBLANK( lgmattrr[clomatdte] ) )
     )

I also need one to show the all-time open matters per fee earner, so I need the measure to ignore the date filter but include the filter for [solcde].

I've tried a few things using ALL() and ALLEXCEPT() but they always show the same number across all fee earners.

As a workaround I referenced the facts table in Power Query, filtered by clomatdte = null dropped all the columns except fee earner and related that to the fee earner table, then do a simple countrows() across that. Seems like a bit of a kludge though, I'd love to know how to do this in DAX without creating new tables in the model, if possible.