s6-socklog with -i ipport option

The clientip_clientport output seem incorrect in s6-socklog output when
using "-i ipport" option.
Example to reproduce; run
$ s6-socklog -i 192.168.21.1:10514

Then send test syslog message to s6-socklog listening on the UDP port
(here using "logger" on x86_64 debian linux)
$ logger -n 192.168.21.1 -P 10514 "Sample log message"

The (start of) s6-socklog produced log line "clientip_clientport" looks
(usually) something like this:
5511368.21.1_: user.notice:

Can anyone else try to re-produce/confirm?

-J