Huawei has especially aggressive battery management which just shuts down background apps. I’ve noticed this with safety apps where you share location with family, and apps such as Prey which can help you locate your phone if it is stolen or lost.
For fresh installs it’s not often a big issue as the app should request all the permissions it needs including prompting to switch off battery optimisation, but many updates for apps are not checking these permissions.
If you run any such apps it is well worth testing with your friends and family to check locations or whatever are sharing like they should. Do not wait until you have the emergency.
See COVID-19 tracing apps may fail to notify exposed users due to aggressive OEM battery saving measures
We’ve extensively reported on OEMs that needlessly kill useful background processes to save battery life, creating problems like missed notifications and