“ The loss of communications was expected, because a hill stood between Ingenuity and Perseverance, which acts as a relay between the drone and Earth.”
https://www.space.com/mars-helicopter-ingenuity-breaks-63-day-silence
“ All communications to and from Ingenuity must be routed through Perseverance. That explains the recent silent spell, which the two mission teams had expected: The rover had disappeared behind a hill from the helicopter's perspective, and it didn't come back into view until June 28.”