S25 is still new. Perhaps next updates will resolve this.
The same thing happened to my Facebook messenger in S23 Ultra and S24 Ultra when they were still new (I'm not planning to buy a phone this year).
Meanwhile, i think all you can do about it, esp if you have important emails, is be sure the app is not sleeping or is given unrestricted battery use and is allowed to use data even while data saver is on. Of course all preferred types of notifications are allowed and included in permissions if applicable. And be in the look out for new updates in the app and and OneUI.
