Why would DNS stop working after a while in non-systemd MX Linux?

I am using MX Linux, without systemd. Sometimes after a while, and every time after sleep or hibernation, domain name resolution stops working, that is ping 8.8.8.8 works, but ping google.com does not. I have to reboot **twice** before it can work again, relogin does not help. I also know it is (probably) not hardware related, because I had the same issue on a new notebook and a fresh MX Linux install. I know this is not a support forum, so my question is: what could cause MX Linux to lose the ability to resolve domain names after sleep?