Apologies for the thread necro, but I just noticed this happening on my system, too, but with a little wrinkle. I'm running @davidc502's custom build for WRT32X, dual-stacked with a HENET IPv6 tunnel and delegated /48 and a relatively large Adblock list loaded in (~88k entries).
I've only noticed this in the last few days, but going back through my syslogs I can correlate a DHCPACK to my Playstation 4 with two reloads, one after the other, of dnsmasq 2-3 seconds later. No other clients on my LAN appear to be precipitating this behaviour.
The PS4 is requesting an IPv6 lease, as are many other clients on my LAN.
This isn't service affecting, as dnsmasq continues to respond to DNS queries during the reload, but I thought it was worth mentioning.