Download Axioo AX5 stock ROM from here, flash it in your device and enjoy the native Android experience again. The download file contains the USB driver, flash tool, and the scatter file.
Download Axioo AX5 Firmware
Stock ROM File Name: Axioo_AX5_MT6737M_20171104_7.0.zip
Stock ROM File Size: 995 MB
Android OS Version: 7.0