The Heavenly Language Immortal Venerable didn't pay much attention initially, but upon inspecting closely, she discovered that Chen Lu's Qi Fortune was exceptionally dense. However, he seemed to have means to shield himself from the Heavenly Mechanism, which obscured his dense Qi Fortune, hence she didn't notice earlier.
At first, seeing Lu Chen as merely a Heavenly Immortal, she didn't intend to investigate seriously, which is why she overlooked the enormous Qi Fortune on him.
If Lu Chen hadn't consecutively defeated Golden Immortals twice, and this time his battle with Liu Cai was personally observed by the Heavenly Language Immortal Venerable, she wouldn't have any serious thoughts of investigating him.
