Rod of Alertness

The Rod of Alertness doesn’t give a passive perception of +5 in the DMG. Am I wrong with saying that it shouldn’t have that effect in D&D Beyond?

Quote from FourOverFour >>

The Rod of Alertness doesn’t give a passive perception of +5 in the DMG. Am I wrong with saying that it shouldn’t have that effect in D&D Beyond?

 The Rod of Alertness grants advantage on Perception checks. You can find information in the Passive Checks section of the Basic Rules the following: 

If the character has advantage on the check, add 5. For disadvantage, subtract 5. The game refers to a passive check total as a score.

Hope that helps!