Hi there, I've tried a lot of things, even installing one of those "push notification fixer" apps, and it didn't work. Is there any way to make the phone instantly recieve all notifications without a delay? Like some settings in configuration, or accesing the developer options and modifying some parameters. I get them on time when the phone is unlocked, but I really need to get them on time even when the phone is locked.

hello,
did you install any antivirus applications on your phone? because some antivirus apps will intercept the notifications for your phone.
you can check it.
and please tell us your firmware version and we will report to the tech team.
thx.