When navigating to a log entry that includes an IP range, there is no link to the IP range in question. This seems to be affecting both IPv4 and IPv6 ranges. See attached screenshots.
IPv4 example: https://en.wikipedia.org/w/index.php?title=Special:Log&logid=111668309
IPv6 example: https://en.wikipedia.org/w/index.php?title=Special:Log&logid=115537432