Do you have a file /etc/eos-update-notifier.conf.pacnew?
Can you show the output of command
cat /etc/eos-update-notifier.conf | eos-sendlog
There are other programs (like @Kresimir pointed out) that can handle updates, which means an update notifier is not really needed. Especially because on a rolling system updates are very frequently available, typically many times a day.
However, I’d recommend using command
eos-update --aur
for updating.
And option --aur is needed only if you have installed software from the AUR.