@monstrocity
Hello!
Eddie handles DNS by itself. As @OpenSourcerer noted, Eddie runs Hummingbird with --ignore-dns-push. This happened even in the past, but HB 1.1.2 now logs more accurately and warns you that it has been ordered to ignore DNS push. Therefore you should upgrade to HB 1.1.2 and not use older versions anymore.
An important implication of the above choice for Eddie is that Eddie + Hummingbird is not usable in systems where systemd-resolved is configured to not respect /etc/resolv.conf settings (example: Fedora 33 and 34). In such systems Eddie should not be used as it can not handle DNS, while Hummingbird and Bluetit can.
No, it's not a compatibility issue, it's only that Hummingbird by default handles DNS push.
We can't reproduce the issue, can you please send us HB log showing the problem and any (if any) additional clue to reproduce the problem? Can you also tell us what you mean exactly with "Only logging out or restarting"?
Kind regards