A quick look at the latest UK Regulation:
LLaw 1178_2011 12 May 2021.pdfaw 1178_2011 12 May 2021.pdf
Law 1178_2011 12 May 2021.pdf Page 680
Law In Force Version 2 of 2 31 December 2020 -
Present Subjects Aviation
1. Pilot licences A pilot licence issued by [the CAA]1 in accordance with the national requirements shall be converted into a Part-FCL licence provided that the applicant complies with the following requirements:
PPL(A) ≥ 70 on aeroplanes Demonstrate the use of radio navigation aids PPL(A)
So if they haven't done it REG 6 Appeal.