Davide Masserut <dm@mssdvd.com> writes:

> New messages are usually indicated by the overlay arrow.
>
> When `rcirc-omit-mode' is enabled, the arrow doesn't appear if the previous message
> is omitted (by default "JOIN", "PART", "QUIT", "NICK" messages) but the
> mark to the first unread message is still set.
>
> Steps to reproduce:
>
> (add-hook 'rcirc-mode-hook #'rcirc-omit-mode)
> (add-hook 'rcirc-mode-hook #'rcirc-track-minor-mode) ; optional
> (setq rcirc-server-alist '(("irc.libera.chat" :channels
>                            ("#emacs" "#libera" "#linux") ; active channels
>                            :port 6697 :encryption tls)))
> (rcirc nil)
>
> Then:
> - wait for new messages to arrive
> - switch to the channel buffer
>   (with C-c C-SPC if `rcirc-track-minor-mode' is enabled)
> - jump to the first unread message with C-c C-a
> - check if the arrow is there 
>
> To see omitted messages set `rcirc-debug-flag' to t before calling
> `rcirc' or start another irc client without enabling
> `rcirc-omit-mode' or similar features and join the same channels.

Could you test if the following improves the situation: