Weird Behaviour

Hi there.  I have NextDNS installed on my PC, my phone, my iPad and also set on my Firewalla router.  In the analytics,  it shows each device separately, but the total of the other devices - PC, phone, iPad - is greater than the number of entries on the router. 

Seeing as they are all going through the router (except some on the phone when I am out and about) why do the totals not equal what is going through the router?