I can’t join my sisters world

Me and my sister are on the same WiFi, she can join my world but I can’t join her world

I logged out of my account and rejoined but it still won’t let me join hers and she also tried everything in her device but we found nothing, her friends can join her but specifically my device won’t , we tried everything, please fix this Mojang (I’m the sister writing , my brother is 6 so I feel bad I want him to play with me but he can’t,please fix it)