They fallback to unjammable guidance, usually INS but
possibly TERCOM or AI target discrimination in the modern day. Russia uses sub-$300 hardware like the Nvidia Jetson to enable semi-autonomous loitering strike capability in their Shaheds:
https://www.techspot.com/news/108579-russia-field-testing-ne...GNSS is also cheap, precise and difficult (although possible) to jam. It's probably the preferred guidance on strike drones operating outside the regular theater, where GPS are less denied.