Posted: Sat May 7, 2022 10:48pm
"It's a Schengen Rule"
Please elaborate as to why you are quoting this rule.
You should be aware that the UK was never in the Schengen Travel Area - we always had to show our passports when entering the Country.
From Wiki -
Of the 27 EU member states, 22 participate in the Schengen Area. Of the five EU members that are not part of the Schengen Area, four—Bulgaria, Croatia, Cyprus, and Romania—are legally obliged to join the area in the future; Ireland maintains an opt-out, and instead operates its own visa policy. The four European Free Trade Association (EFTA) member states, Iceland, Liechtenstein, Norway, and Switzerland, are not members of the EU, but have signed agreements in association with the Schengen Agreement. Also, three European microstates—Monaco, San Marino, and the Vatican City—maintain open borders for passenger traffic with their neighbors, and are therefore considered de facto
members of the Schengen Area due to the practical impossibility of
travelling to or from them without transiting through at least one
Schengen member country