Currently ALL newer flagship models are affected by delayed notification issue for at least past 6+ months, which started happening after around may 2018. Most devices are affected such as: S7, S8, S9, Note 9 and similar.
This is related to "doze" feature of android phone, where samsung optimization whitelist options are not working correctly thus affecting almost all samsung phones.
The issue is reproduced during following scenario:
1. User locks phone, waits around 5m
2. App sends notification (which is not marked as PRIORITY in google push services).
3. User does not get notification
4. User unlocks phone, and suddenly multiple "delayed" notifications arrive.
Multiple users has reported the issue and tried various workarounds such as:
- Disabling battery optimization for certain apps
- Disabling all battery optimization options
- Making sure "WIFI" connection is always maintaned, even during sleep mode
- Making sure DATA connection is always maintaned
- Restoring device to factory
- Totally replacing devices with new ones.
- Wiping cache and similar
There is currently only one temporarly solution working, which is disabling doze using adb console. This workaround is temporarly and works until next reboot. It requires setting phone to debug mode and connecting to it.
"adb shell dumpsys deviceidle disable"
Samsung is totally ignoring the technical issue since at least 6 months or more. There are multiple threads all over the web about such problem existing. Examples:
The issue is making phone totally unusuable for people who rely on instant notifications, such as alerts related to financial services like declining stock rates and similar. I dont understand why such critical thing like delivering notifications in time is totally ignored by samsung. The issue is not present on any other android phones.
If you have ability to contact someone of samsung development team, please forward this thread to make sure there will be finally reaction. Please reply to this thread if you have same issue.
Very good. Now each of us must spread the voice of this petition on change.org all over the internet, in every known forum that might be relevant, as well as to inform the friends having Samsung phones equipped with Android Oreo or above.
After detailed testing in previos period, I noticed that some apps (Viber at first place), working fine after turn off battery optimization for messaging apps. But, most problematic app is Gmail. Sometimes, mails delayed more than hour. I tried to explore Gmail sync settings and noticed that Google account sync time for Gmail is related to delayed mails. Although, I turn off battery optimization for Gmail, Google account sync delayed. I think that this problem is related to bad battery optimization for some apps.
In my case, the ADB command didn't totally fix it. It has improved, but I still get delayed notifications after longer periods of not using my phone, like an hour or so. This is very annoying, I can't just leave my phone there and rely on it. I have to keep checking for important notifications like Gmail, for example. It's good to know that it's probably not related to the Google account, at least. I wouldn't want to be making another account just for this. Thanks for creating that petition, already signed it. I'm certainly considering another brand for my next phone.
Regarding problems with Gmail, I found this topic: https://www.reddit.com/r/Android/comments/6s9vth/gmail_sync_email_pushing_is_intermittent/
I understood that problem with delayed mails is related with priority of push notifications for mails. At this point, I found that only workaround for me is switching to Samsung Email app. That app has setting for account sync period and minumum period is 15 minutes. I tested Gmail sync account with Samsung Email and mails received after 15 minutes, in worst case.
Here are the results of my test on my Galaxy S9+
I programmed Google Calendar events every 15 minutes and I recorded the notification arrival times with a resolution of one second. Of 49 events, 6 notified acceptably (but not great), 37 notified late and 6 very late. Here are the recorded results of my test in a PDF file : https://drive.google.com/open?id=1NjyjSF9qzrmRSM15soIjOJe4yka8aKC1
Other applications also have late notifications but I used Calendar as it is easy to program many events at known times.
Thank you for taking time to detail research. But this will not solve the problem unless Samsung accept it. Only way reach to them is forward petition to everyone you know and groups to sign it. They may be react then.
If you are looking here then please sign and share this petition on social media, WhatsApp etc to reach it to Samsung. There is no other way for us to pass this issue to samsung as they totally ignored.
It would be great if others could do a similar detailed test. It takes a LOT of time and effort. I have spent more than 12 hours doing that test and publsihing it because I thought it was important to have precise measured results, not just impressions. I have done more than my share. Now others can do a similar test, publish it and sign the petition. Complaining here is clearly not enough. I have signed the petition and will forward it, but others have to join the effort. Cheers.