There's no specific change from a default config, to retain footage during a loss of pure connectivity, but I would just check your Quality & retention settings - whether you have Motion-based retention enabled or a Recording schedule set up. for motion-based, you should still get the last three days anyway - the camera only starts snipping out static footage once it's three days old. Schedules record nothing outside the prescribed timeslots.
Assuming all is OK there, I'd maybe see if you can replicate the issue and involve Meraki Support in troubleshooting.
