Why are my apps being closed?

I have a huawei p smart 2018.

Since I've had that, I haven't received any notifications from WhatsApp or Microsoft Teams when I have received a message.

Today I saw that WhatsApp and Teams say "finished" when using the battery.

I suspect that it has something to do with the fact that I don't get any notifications, because Telegram says "active" and I always get a notification.

I would be very grateful if someone would answer me.

Maybe you activated the energy saving mode.

No, and I also switched off energy saving mode

Could be the impact of US sanctions against Huawei. US companies are no longer allowed to work with them.

Telegram belongs to a Russian oligarch who doesn't even care what Putin is asking of him…

Android has a battery optimization. Go to Settings and Programs, find the respective program and deactivate the battery optimization / energy saving optimization there.

I've done it before, but thanks anyway😊