[Samsung Galaxy S7 Questions and Answers] TomTomGo!:
I know there are already threads regarding similar issues but I couldn''t find a solution that works for me so far. So I want to describe the problem in detail once again and also summarize possible solutions (which unfortunately didn't work for me so far).

I've got serious problems with syncing my e-mails via the gmail app for several weeks now.

I think that the problems exist since I updated my Galaxy S7 to Android N, but since my phone has been repaired at approximately the same time as the update came out, I can't be sure whether it is because of the update or because of the repair (if a repair could cause something like this at all..?).

Sometimes I get gmail-notifications just in time when an e-mail arrives (the way it should work).

But most of the time I don't get notifications at all or I get notifications with an enormous delay - e.g. I get an e-mail at 09:00 am and the notification comes in at 07:00 pm!

I've recognized that it seems not to be only a notification issue, but a sync issue as well: Sometimes when I go into the gmail app, at first it doesn't show me the mails I've missed the notification for.

Sometimes the mails appear within seconds when opening the app and sometimes I have to open the app and pull down the list (sync manually) 2-3 times to receive the mails. The sync at first pull sometimes is much shorter and doesn't show new mails, syncing 2nd or 3rd time takes a bit longer and shows the mails.

Also the gmail symbol in the notification bar used to disappear in the moment I opened the app or the mail. Since I have the described problem, it takes several seconds for the gmail symbol to disappear (sometimes I've already opened the mail and gone out of the app and it disappears a bit later when I am on the homescreen or in another app).

Moreover I've realized that sometimes when I open my gmail inbox on a notebook/desktop, I suddenly receive the mails (with notifications) on my phone (as if by opening the inbox on my notebook, gmail sends a sync signal to my phone).

Here are my settings which I thought/read of might be relevant for gmail to work properly

(Sorry if some setting names are not 100% correct, I use my phone in another language):

In gmail app: gmail sync: activated (999 days), label administration: all labels set to sync all mails, notify for every new mail: activated

In account settings: gmail sync: activated

In app settings: gmail: notifications: enabled

In battery settings: energy saving mode: off, battery optimization for gmail: deactivated

In wifi settings: wifi turned on in standby: set to always (btw the problem doesn't only occur in wifi, most of the time I use 4G)

In data usage: data saving: off (still I set gmail to allow unlimited data usage IF data saving was activated)

I've also already tried the following:

deactivate and reactivate gmail sync in account settings

delete google account, clear cache in recovery mode and again add google account

clear gmail app data and cache, uninstall updates and deactivate app, clear cache in recovery mode and again activate and update app

download the installed firmware for my phone ("G930FXXU1DQB7_G930FVFG1DQB7_MOB.zip") from sammobile and newly flash it via odin

Unfortunately none of the above solved my problem. I've nearly missed some important meetings because I didn't receive the mails in time and it drives me crazy!

With all my previous smartphones gmail sync and notifications worked well.

Do you have any ideas/tips/tricks/hints/recommendations what else I should check or which settings I should consider?

How can I get rid of this problem?

Do you use gmail app on a Galaxy S7 with android N and don't face this problem? If so, what are your settings?

If other users don't face this problem, there must be a solution for me.

I guess this can't be a hardware-related issue..?

Greetz

EDIT: Additionally I've realized sync issues the other way round: When I read or delete mails on my phone, it sometimes happens, that when I open my Gmail inbox on my notebook I still see the deleted mails and the read mails (as unread). When I then pull down in the app on my phone to sync, the mails disappear on my notebook.