ERR_CONNECTION_REFUSED after installation when trying to access the page

Hello dear Nextcloud support community,

I have a small problem with my installation and after some research I have no further idea what else to try. Namely, I started an installation on my Raspberrypi 3b+ and did it without any errors / error messages. Now comes this part:

First, visit xxx to activate your instance of NC, and save the automatically generated passwords. You can check or reset them at any time
You can check or reset them at any time using xxxx and xxxx.
Second, type ‘sudo ncp-config’ to further configure NCP, or access ncp-web at xxxx.
Note: You will need to add an exception to bypass your browser’s warning when you
the first time you load the activation and :4443 pages. You can run letsencrypt to get rid of the warning
You can run letsencrypt to get rid of the warning if you have a (sub)domain available.

I’ve made the IP’s unrecognizable with X. Privacy and Security.

But now my problem is that I can’t access any site at all, because every time I connect I only get this message:

The website is not reachable
192.XX.X.XX has refused the connection.

ERR_CONNECTION_REFUSED

The connection (allow exception) was not shown to me as unsafe or similar. I also disabled my antivirus program once as a test while I was trying it out.

I also noticed that I could previously access my Pi via a remote desktop connection, which no longer works.

I once attached the ncp-report log.
For the installation I followed this guide:

There I was given this option for the installation:

wget https://raw.githubusercontent.com/nextcloud/nextcloudpi/master/install.sh
sudo bash install.sh

Is this the first time you’ve seen this error? (Y/N):
Yes

Output by ncp-report - Pastebin