Persistent app crashes, strange behaviour, or suspected malware that survives a factory reset can be eliminated by a clean firmware installation.
To download the Nokia C30 firmware, follow these steps: Nokia C30 Firmware Download
I can point you toward the exact tool versions and firmware configurations for your setup. Share public link Persistent app crashes
Because of the Unisoc processor, standard tools like Mi Flash or Odin will not work. You need to download the official (also known as ResearchDownload or FactoryDownload). Step 2: Install Drivers and Extract Files Nokia C30 Firmware Download