Sim not recognised due to custom rom? topic

Hi folks,

I have two phones, the s4 mini and the z3 compact. While in Western Africa (Mali) I just noticed that the Malian sim is recognised by the Z3c (stock rom, not even rooted) but not by the s4 mini which is rooted and runs on liquidsmooth.
Can this be due to the custom rom? Has anyone else experienced this and can help me and would flashing a stock rom solve the issue?

Thanks