First of all, your device doesn't support 5G so cross that out, the Galaxy A10 only supports 4G. Second, make sure that your area has a good cellular signal, this is usually the problem with poor network coverage. Third, make sure your cellular sim is 4G/5G ready, though simcards bought eight years ago support this already, this shouldn't be a problem.
Thank you for letting us know about the connectivity issues with your Samsung Galaxy A10.
We understand what you're going through when you try to troubleshoot your device on your own by trying all available reset, but isn't working as you expected.
Don't you worry, we are here to help, provide quick fixes, and offer solutions to your device problems.
Both, we will figure out what's behind the issue/s and other possible reasons and come up with the solutions by following below steps.
A) First, ensure that your device is up-to-date with the latest Software updates.
Settings > About Phone > Software Updates > Download and Install > Follow On-screen notifications.
B) Check the network connection.
Check to see if your internet connection signal is strong. If your network coverage is poor, you might experience the mobile connectivity not working properly. Please reconnect to the Wi-Fi and/or Router with strong network coverage to fix this.
And/or contact your Mobile Network Service provider in order to find out the signal in your coverage area.
C) Turn Off and On Wi-Fi again.
Restarting your Wi-Fi connection by turn it off and back on, simply swipe down the quick-setting panel and tap the "Wi-Fi" shortcut.
D)Turn On and Off Airplane mode.
You probably haven't tried turning on and off the airplane mode while trying to fix your Wi-Fi not working. All active connections are simply cut off when airplane mode is turned on, and they are restored when airplane mode is turned off. This could also resolve the problem with your Wi-Fi not working. To disable airplane mode, please pull down the quick-setting panel and tap "Airplane mode," wait a few seconds, and then tap it again.
E) Enter Safe Mode and check whether the Wi-Fi works fine.
Long-press the power button to launch the power menu.
Now long-press on the 'Power off' menu until a window appears.
Tap 'Yes' on the screen to reboot into Safe Mode.
F)Running the Diagnostic Tools under Samsung Members app.
Step 1. Run Samsung Members and select Get help on the lower half of the screen.
Step 2. Tap View Tests located under Diagnostics.
Step 3. Diagnostics checks, Individually Tap the following;
" Wi-Fi"
Step 4. Your Samsung Galaxy phone will then run through the checks.
Step 5. Follow the on-screen instructions to complete the check.
Step 6. You can view your results after each check is complete.
G) Close all Apps running in the background and check/remove unnecessary apps.
H)Enable Google Location Accuracy.
Google estimates your location data using Wi-Fi, Bluetooth, Mobile Data, and GPS to improve accuracy on your mobile device. If your location doesn't work, turning on Google Location Accuracy might help.
Simply draw down the quick-setting panel.
Tap and hold on the 'Location' shortcut to go straight to the location settings.
Tap "Google Location Accuracy" and then toggle on the service.
I) For more assistance, you may contact us on our online Samsung support channels below.
