This train has a slip route from UMB to KLK.
When you will search from KLK/CDG to UMB then slip train 20926 ( 22926 as regular ) will come as result.
This slip will be no more after October, but active currently so you are getting in your search.
If you will search CDG to UMB or further route of Paschim express after 6th...
more... October then you will see only 02926 or ( 12926 in regular ) because Paschim express will be diverted to CDG from UMB and run till Amritsar.