What should be done to fix this issue?
Let's go straight to the point here. If you haven't yet tried a soft reset, then I suggest you perform a soft reset on your Galaxy S5 right now. This is how it's done:
1. Remove the battery with the phone still On.
2. Wait for 30 seconds and re-insert or replace the battery.
3. Turn the phone back on.
4. Allow your phone to re-establish network connection for a few seconds.
5. Now check if there are any improvements. Otherwise, proceed to the next step.
6. Check the Airplane mode and make sure it is disabled or inactive. To get this done, just press and hold the Power button for one to two seconds. If you see Airplane mode is OFF, then that indicates Airplane mode is not active and you're good. Otherwise, touch Airplane mode to turn it off or disable the feature.
If problem persists, continue with checking auto reject settings on your phone. Follow these steps:
How to check auto reject settings on Galaxy S5?
Following are the steps to verify that no call restrictions like Auto Reject are enabled on your phone.
1. Touch to open the Phone application.
2. Touch Menu.
3. Select Call Settings.
4. Touch Call rejection.
5. Touch Auto reject mode and turn it OFF.
After you've verified the auto reject mode is disabled, place a test call to your phone. If it did not solve the problem, please proceed with verifying Blocking Mode is not enabled on the phone.
Please note that when Blocking mode is enabled, all calls to the phone will be sent directly to voicemail, unless you have added numbers to the Allowed contacts list manually.
Here's how to check Blocking mode settings on Galaxy S5:
1. Go to the Home screen.
2. Touch Menu.
3. Select Settings.
4. Touch My device.
5. Touch Blocking mode.
6. Touch the ON/OFF slider to turn Blocking mode OFF.
7. After ensuring blocking mode is disabled, place a test call to your phone and see if it works fine now. Otherwise, continue with the next procedure.
Check the phone for restrictions like call barring and call forwarding.
This time, you have to ensure call barring is disabled on the phone. Follow these steps:
1. Touch Menu from the Home screen.
2. Touch Settings
3. Touch My device.
4. Touch Call.
5. Touch Additional settings.
6. Touch Call barring.
7. Verify and make sure both options for Incoming when roaming and All incoming calls are unchecked.
8. Now verify if call forwarding options are not enabled on your phone.
a. Get back to the Home screen and touch Menu.
b. Select Settings.
c. Touch My device.
d. Touch Call.
e. Select Additional settings.
f. Touch Call forwarding.
g. Verify and ensure all call forwarding options are turned off or disabled.
You may also want to know what causes this problem to occur on your device? Well, here's what you need to know first.
Among the most possible reasons as to why calls are being forwarded straight to voicemail are as follow:
1. Number was recently ported. Please note that when you recently ported your phone number from one service provider to another, you will likely encounter this problem. Typically, this can last a few days until your phone number is completely ported. So all you've got to do is contact your mobile service provider and let them take note your concern.
2. Account is not set up correctly.
3. Third-party app.
4. Inconsistent network connection.
5. Use of incorrect SIM card.
6. Call barring/restrictions are enabled.
7. Blocking mode is enabled.
8. Airplane mode is enabled.
9. Device software requires update.
10. Network outage affecting voicemail services in your location.