MacOS & NextDNS client / dns stops working suddenly

Hi all,

I have recently installed the NextDNS client on my MacOS. Version 1.4.3 (19), using IPv4 and IPv6

I observed now several times that after a longer while (a day, more or less) the DNS resolution simply stops working. 

It starts working again if I stop the NextDNS client or if I pull the wired network cable while Wifi stays on.

Is there any troubleshooting I can do please?

thx