S21 Lots of issues with new update

[Borrino3]

I just updated my phone and am now having issues with it saying I don't have a Sim card as well as the battery keeps dying extremely fast and getting very hot to the touch which never happened before. Also wifi calling doesn't even exist on my phone anymore. If this issue doesn't get fixed I'm going to have to switch to iPhone because even my boyfriends s23 is doing the same thing after the update. This update is absolutely horrendous. I've seen some threads on reddit speaking on the same issues and a lot of people are planning on switching to the iPhone as well. 

[JAMES4578]

Hi @Borrino3  Welcome to the Samsung community:)

With the sim /wifi calling issue firstly I would suggest resetting the Network connections, General Management-Reset-Reset All settings.  However you may need to remove sim card and check all is ok there, restart Device without the sim and then insert again.

Did you clear the cache partition after update as that is advisable, temporary cache files are deleted but your Data is intactand may help with Battery issues.

1. Turn off the device.
2. Connect To Computer , other Device or TV USB, Press and hold the Volume Up key and then press and hold the Power key
3. When the Android logo displays, release both keys.
4. Wait until the Android system recovery menu options appear.
5. Press the Volume down key several times to highlight wipe cache partition.
6. Press Power key to select.
7. Press the Volume down key to highlight yes, them and press the Power key to select.
8. When the wipe cache partition is complete, Reboot system now is highlighted.
9. Press the Power key to restart the device.

However after the update the device does go through a learning phase for up to 14 days and Battery may well drain a bit quicker during this time.

you can also Reset the Battery stats , with Auto Blocker switched off dial *#9900# in the Samsung phone App and scroll down to Batterystats Reset .   Now restart Device for this to take effect.  credit to  @lminvti ,@Moiramon and @Piper123  who have also  mentioned this recently.