Marvel Future Fight can't disable notifications

I have installed Marvel Future Fight v3.2.0 on my Android phone (Xperia Z1).

In the Settings, it has a few tabs regarding different types of settings.

I intend to disable notifications, so I selected the Alert tab.

When I change to a tab other than ALERT, I can see different settings but when I change to the ALERT tab, it stucks there - meaning that even if I click another tab, I still see the All Notifications (on/off) settings.

If I select the Option tab after Alert:

Also, when I change it to off, the OK button is not saving the setting.

Looks like a bug or I try to set it wrong. I tried to reinstall it but no change.

Can you confirm?

If the app doesn't allow you to turn the notifications off, you can still ask android to do it for you.

In Settings/Sound and Notifications/ (Sometimes just Settings/Notifications), you have a list of all installed applications, and can turn notification to off for any of them.