The capacity that the tabular model has brought is a huge step forward, switch from MDX to DAX six years ago and not looking back! 
😎

Good catch Luis 😉
😎
Without further information, all input is speculative and not accurate enough.

The XML DML is a little cumbersome but this examples should get you going
😎
Before
<bd>
<cat>
  <grp>
  <ben>
   <bn_id>11</bn_id>
  ...

Have a look at this article: "How to troubleshoot Error 3414 and a failed database recovery with SQL Server"
😎

First thing to check are the joins, looks like there is something missing there as hash match inner join is producing 3.18 x 10^9 rows!
😎

I would...

NOTE: This method is about 10-15% slower than the CASE statement!
Here is an alternative which brings the last non-zero value
😎

SELECT
 ...