It doesn't have to be true to be personal

In some versions of my book I have (section entitled Thoughts on Privacy - paragraph 'Is It Personal') stated that falsehoods or inaccurate information attributed to an individual likely would not be considered personal information. I still believe that to be true in most cases but in accordance with the ICO even if the information is inaccurate or untrue but in fact relates to an identifiable individual it may be considered personal information. In short, even if the facts are inaccurate, if they would permit an association to an identifiable individual, they could be considered to be personal information.

..... Please see the ICO document 'What is the meaning of 'relates to'?

https://ico.org.uk/for-organisations/uk-gdpr-guidance-and-resources/personal-information-what-is-it/what-is-personal-data/what-is-the-meaning-of-relates-to/