Neil MceEvoy's "Plaid Genedlaethol Cymru." seems to be deliberately confusing.

Nation Cymru report that

Independent Assembly Member Neil McEvoy has registered a new party called the Welsh National Party.The new party was registered on the 15th of January, according to the Electoral Commission.Neil McEvoy, who was originally elected for Plaid Cymru to represent the South Wales Central region before being expelled in 2017, is listed as the party’s leader.“I confirm that we have registered the Welsh National Party. Exciting news will follow in the near future,” Neil McEvoy told Nation.Cymru.

The Welsh translation of the party is Plaid Genedlaethol Cymru. The party registration also includes three images – one an outline of Wales and two of the Welsh dragon.
Neil McEvoy is expected to challenge First Minister Mark Drakeford in the Cardiff West constituency at the next Welsh Assembly election in May of next year. The new party is registered to an address in the constituency.
Assembly Member Neil McEvoy withdrew his application to re-join Plaid Cymru in July of last year.
He cited an “absence of natural justice” and “due process” as the reasons behind the move.
Plaid Cymru’s AMs voted to suspend the South Wales Central AM in October 2017.

The fact that the translation Plaid Genedlaethol Cymru. (Which was Plaid's original name) could cause confusion among voters seems to have passed by the electoral commission.

One of the motivations  motivation behind the e Registration of Political Parties Act 1998 (c. 48), was the use of the names Literal Democrats, Conversative Party, and Labor Party by people in elections in the 1990s; these names were criticised as potentially confusing with the names of the three major parties in the UK (the Liberal Democrats, the Conservative Party and the Labour Party, respectively). In the 1994 European Elections, Richard Huggett stood as a Literal Democrat candidate for the Devon and East Plymouth seat, taking more votes than the Conservative Party margin over the Liberal Democrats, leading to a legal challenge by the Liberal Democrat candidate.^[1][2]

The legislation therefore introduced a register of political parties; and included provisions to prohibit "confusion" with already-existing parties, names that were "more than six words", or were "obscene or offensive".

As the act also permitted logos on ballot papers, the act also introduced a similar register for emblems, which had the result that the Communist Party of Britain is the only party in the United Kingdom permitted to use the hammer and sickle as its ballot-paper logo, although they usually use the hammer and dove variant. Parties may register more than one emblem, or none at all; most have two or three.

The act was amended by the Political Parties, Elections and Referendums Act 2000 (2000 c. 41) to change the registration authority to the Electoral Commission from "the registrar or other officer who performs the duty of registration of companies in England and Wales under the Companies Act 1985"

it seems clear to be that the

Welsh Title of McEvoy's party will cause confusion especially if it is given prominence over English on the ballot paper and it seems the Electoral Commission may not have considered it.