Hi RD Grace - No if you are not changing the registered extent (red outline)
A surveyor (RICS) can help in such scenarios -
Boundary disputes mediation service | RICS
I would encourage you and your neighbour to try and resolve it yourselves if you possibly can but of not then seek legal/professional advice as appropriate
There is no 'All' with regards this forum - it will only be HMLR who generally respond. If you are looking for wider online comment then try other public forums such as Garden Law where such matters are often aired and shared