I have a Samsung A3 Galaxy SM-A300F from 2015.
Some of the apps won't sync when the phone is connected to wifi, even if sync is turned on. It comes up with a network error. For example, OneNote and Gmail won't update on wifi. Signal will let me connect and post, but not do certain things like change my profile pic.
When I use Fairmail to get my email however, that works fine.
I can only do these things, on these specific apps, when connected to data on my plan.
I've got a tablet and a second phone and both of those connect, sync and update everything on my wifi, including the apps mentioned above. So it's not the actual wifi on the ADSL router, its the A3 that is the problem.
The A3 does connect, just won't allow certain apps or even functions in certain connected apps to update, even though it IS connected to wifi.
I've checked all the network settings on the phone and can't see anything amiss. I've deleted and reacquired the network too.
Thanks @MrRS5 yes, I'm aware its pretty old and I'm considering upgrading, but I'm still using the A3 as it suits me fine and I'll risk the security updates for the moment. Its just one of those niggly things that I can't work out why its happening. The sim tray is jammed shut too, so I'll have to get them to send me a new sim.
I actually found that i had a software update, so I was hoping this might fix the issue. Nope, same issue. Got to use mobile internet to sync Gmail and OneNote. Oh well.