Hi
I refer you to the UK/Italy Double Taxation Treaty (DTT) available at:
UK/ITALY DOUBLE TAXATION CONVENTION
A company is resident in the UK due to its incorporation here or where the central management and control of its business is in the UK.
If the Italian Tax Authority also consider the company to be resident in the Italy, then the tiebreaker in the DTT between the UK and Italy would need to be considered.
It is unclear from your question whether the you as the sole director intend to be resident in the UK or Italy which is a factor you will need to determine as that will be a consideration in establishing central management and control.
If the facts and the DTT confirm the company is resident in Italy, the subsequent appointment of directors outside of Italy (or any other changes) could mean that its residency status also changes.
Corporate residency is covered in the link you refer to but there is a much wider guidance starting at :
Company residence