Have you tried wiping the cache partition of your device?
Here are the steps:
1. Turn off the device.
2. Press and hold the Volume Up key and the Bixby key, then press and hold the Power key.
3. When the Android logo displays, release all three keys.
4. An ‘Installing system update’ message will show for 30 – 60 seconds before the Android system recovery menu options appear.
5. Press the Volume down key several times to highlight wipe cache partition.
6. Press the 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.
After the Dec 1 2019 update i had this same issue. The cache clear nor the safe mode worked to solve the problem on there own. I then went in cleared the cache from the recovery menu on the reboot put it directly into safe mode .. For me atleast this worked , phoned finished the stalled update.
That is awesome to hear! Please let us know if you have any additional questions.
I tried all of above: wiped cache and went straight to safe mode and left it alone overnight and still stuck "finishing" the progress bar never got past the "p" in update.
PLEASE HELP! Thank you.