Installing Android upgrade on new S9 is stuck since 4 hours

[Android Central Question]

I bought the Galaxy S9 two days ago and I got asked to do a software upgrade. I tried from home using my mobile data but it required only wifi due to the size.
Today at work, I connected to the company wifi and was able to download the update. And I chose to install now without thing too much about it, since previous upgrades were done in about 30 mns to an hour.
I started the installation at 9.30 am and it is now 1 pm and it still has not completed. I still have a black screen with a message Upgrading Android - optimizing app 112 to 112. No idea what that means but it's been stuck like that since 9.45 am. Any button I touch is not having any effect and I'm worried that if I force restart the phone I will run into issues and loose the benefits.
Of note also, my company wifi does not have the best signal.

two questions for you:
1. is this normal? Has anyone had the same experience or something is just wrong. If not what should I do?
2. Do I absolutely need to be connected on internet for it to eventually complete if not normal upgrade time is as per above? It started while I was on work wifi and I had disabled my mobile data.

Please help as I'm getting very worried!

 

[belodion]

If it’s downloaded you don’t need internet for the installation.

Plug it in to charge and leave it overnight.

If no go, unplug, hold Power to shut down the phone, boot into Recovery, and wipe the Cache Partition.

 

[Rukbat]

two questions for you:
1. is this normal?

No - app 112, whichever app that one is, probably has something wrong with it.

If not what should I do?

Keep it charged. If it doesn't clear up by tomorrow, bring it into your carrier.

2. Do I absolutely need to be connected on internet for it to eventually complete if not normal upgrade time is as per above?

No, it's building an Odex file for app 112 - that's internal, it doesn't need the internet. Don't turn Wifi off, but you can leave the area.