Unread messages in apps

[RebecaM83]

Unread messages in apps
Hello, I just bought the xperia xa1 ultra and I have a problem. When I have unread messages on WhatsApp or emails, I do not get the number of unread messages on the App icon. And if I enter the App and leave without reading the messages, it no longer warns me in any way that I have not read those messages, because even the icon that appears in the upper left corner, is deleted even if you have unread messages. However, in News, Whats news or Facebook if you notify me of unread notifications. Is there any way to solve that ?? Attached image where I explain it better. Thanks in advance!!

Hola, acabo de comprar el xperia xa1 ultra y tengo un problema. Cuando tengo mensajes no leídos en WhatsApp o correos., no me sale el número de mensajes sin leer en el icono de la App. Y si entro en la App y salgo sin leer los mensajes, ya no me avisa de ninguna manera que no he leído esos mensajes, porque incluso el icono que sale en la esquina izquierda superior, se borra aunque tenga mensajes no leídos. Sin embargo, en Noticias, Whats news o Facebook si me avisa de notificaciones no leídas. ¿¿Hay alguna manera de solucionar eso?? Adjunto imagen donde lo explico mejor. Gracias de antemano!! 

[Uliwooly · Accepted solution]

@RebecaM83

I've edited your post as this is an English only forum, you can use Google Translate to reply and/or post. 

This has been asked before myriad times, you can use the search bar and will find the answer, in short, it will be up to the app developer to address this issue. 

[RebecaM83]

Ok. Thanks!!