As usual I ran into trouble with my tripod. I was told that I need a permission to take professional photos. Of course I wanted to know more about me taking photos in the UK and started writing emails to official authorities to get that permission after my return back to Switzerland. It turns out that under the UK law I can take any photos I want to as long as I am on public property. There are a few exceptions like military installations I should not take photos of when standing on public ground.
But I am OK with this; I do not take photos of any military installations or aircrafts anyway.
The people giving me this information were very friendly and apologized for the clowns that told me not to take any photos on a tripod. I also got a complement from them and was told to keep doing what I do; and bring home some nice photos of all the places I will go to in the UK.
I will print out this email whenever I will go back to the UK. I was also told to write down the names whenever something like this happens.
BTW: The day after I had my little “incident” I was going back to the shopping mall (as advised by the security guard). There I was asking for the permission to take photos. The manager there did not know anything about a regulation taking photos on the outside of the mall. He gave me a written statement about it.

Photo Tip: Camera settings when it is dark
I like to take photos during the night! Sometimes it is a little too dark and the camera reaches its max. shutter speed. The maximum duration of the shutter speed when shooting in A Mode varies among the camera brands. For instance my Nikon Z7 has a maximum shutter speed of 30 seconds while my friends Olympus OMD goes up to 40 seconds.
When I reach my max at my camera, I either decrease the F-Stop or switch into M-Mode and select Bulb to control the shutter speed. To know more or less what the shutter speed is, I use a timer on my cell phone.
I just play with it and see what the result looks like after every photo.