I have updated my iPhone SE to iOS 13.1.3 with no issue what so ever.
If you are not able to hear the other person, click this...>If you can't hear a person on a call or voicemail or if the sound isn't ...
If the other person is not able to listen to you then please click this--> If the microphones on your iPhone, iPad, and iPod touch aren't ...
Get your Car audio checked and --> If you can't connect a Bluetooth accessory to your iPhone ...
Call Failed or Dropped Calls
In telecommunications, the dropped-call / Call-Failed rate (DCR) is the fraction of the telephone calls which, due to technical reasons, were cut off before the speaking parties had finished their conversational tone and before one of them had hung up (dropped calls or Call Failed). This fraction is usually measured as a percentage of all calls.
4 Reasons Your Phone Keeps Dropping Calls or encounter Call Failed and iOS update is not one of them,
- Your Signal Is Weak.
- The Cell Tower Is Overloaded / Heavy Traffic (Telecommunication)
- You've Misunderstood Your Signal Strength
- You are moving and the signal weakens while changing from one tower to another (Carrier's Handshake Issue)
Options Are...
Aliens on your iPhone; What exactly do you mean?