I know this is coming late, but I really thought many of us using this device had solved this issue, but just yesterday I realised not many of us could solve it. The problem is, for some reason after the Marshmallow update, Sim contact names don't usually display on the phones call log or even on messaging apps such as Whatsapp etc.

I noticed mine when I got a call from Mum and her number was the only thing displayed, anyways this method worked pretty well for me,

INSTRUCTIONS:

▪ Create a backup file for your contacts (.vcf), you can do that by using Super Backup Pro
▪ After you have created contact.vcf, select a location to save the file
▪ Now, open Super backup pro and select restore,then restore the contact.vcf file you created before
▪ After restoration is completed, your contacts should now be displayed and save in your phone storage.

Hope this was helpful.

http://www.droidgurus.com/2016/02/how-to-fix-sim-contacts-not-showing-on.html?m=0#more