Presence not correctly rejected after stopping mod_muc

[lovetox]

Environment

• ejabberd version: 18.05
• OS: Linux (Debian)
• Installed from: distro package

Bug description

After stopping mod_muc, the first presence that arrives from a remote server to the muc service domain is not properly rejected with a presence error.

Instead ejabberd terminates the s2s connection to the remote server.

Only the second presence is answered correctly with an error.

After discussion with @zinid it was determined

1. mod_muc is stopped, ejabberd doesn't know anything about conference.domain.tld
2. ejabberd receives stanza via existing s2s stream to conference.domain.tld, but doesn't find it in route table
3. ejabberd terminates the s2s stream with host-unknown
4. you send next stanza and a new stream is rejected with host unknown and you receive the error in the client

[Neustradamus]

@lovetox: It has been solved?