Underline to determine Implicit is not show in below case - Scala Permanently deleted user Created August 21, 2017 09:37 underline is not shown if it as undergone implicit conversion in above first highlighted line
It's very similar to https://youtrack.jetbrains.com/issue/SCL-12375 . Please, keep track of that ticket and let us know if the problem doesn't disappear after it's fix.