You just need to install the Digital Clock Debarred plasma widget:
Once you have added it to Plasma, right click on your existing Digital Clock plasmoid and select “Show Alternatives” to replace it with the debarred version.
I had searched all the widgets for “clock” and “Time” and “date” but did not see that one in the list at all. I think it may have been that it was a few days ago now.
Wonder why on earth someone has to go to the trouble of creating a fork just to get the darn clock on the desktop of an OS correct ^^
Yea, I was going to refer to it as a pipe too, but the odd thing was that when I added a pipe directly to the format string it was not the same, so I assumed it must have been a separator of some design.
Here is a pipe alongside the problematic character:-