Using FullPageOS as a display and touch screen for Home Assistant

[3DPi]

I am running FullPageOS on a Raspberry Pi 3, using the RP Imager to create the image.
I setup a URL http:\192.168.2.17:8123
I expected a display showing my Home Assistant start page, usually with a logon. (First time use only)

Instead I get a Goofy face and "192.168.2.17 refused to connect"

I am using Version of FullPageOS? 0.14.0

I added a URL to a Klipper (Moonraker) instance http://192.168.2.18 and it works perfectly as expected.

Investigation:
Confirmed that URL for Home Assistant works elsewhere, Confirmed it is working on other machines and other browsers.
Returned to Pi 3 added keyboard and mouse, used Ctrl T to open a new Chrome Tab.
I entered the URL http:\192.168.2.17:8123, it presented a logon screen as expected and I logged on. Further attempts to repeat this worked perfectly as expected and I only needed to logon once at the start.

The initial screen continues to fail for this URL only.
Is there something I need to change in FullPageOS to allow Ports to be used, as in 8123, instead of 80?

I am confused as to where I need to look for this problem. Advice appreciated.

[4a6179]

README file says "Webpage can be changed from /boot/firmware/fullpageos.txt" however (at least for me - Pi 3B with 7" touch screen, latest stable version of FPOS) it was located at /boot/fullpageos.txt - I entered my HA URL there as http://192.168.1.2:8123 then saved file & rebooted. After reboot it loaded the login screen perfectly fine as expected.

[guysoft]

@4a6179 It depends if its a Debian pre-bookwork or post bookworm, in the nightly its at /boot/firmware/fullpageos.txt

[guysoft]

@3DPi I am not sure what is your problem - it depends on what port your Home Assistant port is set to. Not an issue, converting to discussion.