Problem with multiple OBB files in xapk packages

I encountered a problem with the specific game "CSR Racing 2" (com.naturalmotion.customstreetracer2). It contains two OBB files, the current version in PlayStore has:

• main.2635.com.naturalmotion.customstreetracer2.obb
• patch.2635.com.naturalmotion.customstreetracer2.obb

Only "patch.2635.com.naturalmotion.customstreetracer2.obb" was extracted. So after starting the game it wanted to download it without success. When I extract the file manually the game works.

Please look into it. I guess it is a more generic problem, not specifically related to this app.