Hello,
GPIO inputs on LimeSDR-Mini should now work with the latest FPGA GW (v1.28). If you compile LimeSuite from source (master branch), running auto update should flash GW v1.28. You can also download v1.28 GW from http://downloads.myriadrf.org/project/limesuite/18.10/LimeSDR-Mini_HW_1.2_r1.28.rpd