Waking Baby Constantly

Help. I’m exhausted and running on fumes. Baby is 5 months, toddler is 2.5 years. Whenever baby falls asleep, toddler screams at the top of her lungs waking baby and making baby cry from being scared. Sometimes when we are at home but always when we are in the car going anywhere it happens.

Ive tried positive reinforcement, distractions, ignoring, explaining, one on one tims, I feel like ive tried everything and I’m at my wits end!

Baby can’t nap well during the day which equals terrible sleep at night too.

Is this just a development thing that she will grow out of or what am I doing wrong????