When Special:CheckUserLog is filtered to a target which is a registered user, it filters the type of logs to 'userips' and 'useredits': https://gerrit.wikimedia.org/r/plugins/gitiles/mediawiki/extensions/CheckUser/+/7eb1a9013520fa021102b4d57e6c01612c143ac3/includes/specials/SpecialCheckUserLog.php#180
It should also include 'investigate' logs.