https://harrypotter.fandom.com/wiki/Dobby's_grave

  Many fans have visited the beach to lay painted rocks, several crosses, and many socks in Dobby’s memorial. However, as the memorabilia has had a negative effect on the environment, the beach asks that visitors just interact with the site by taking photos.[4]

Note: there is currently no indication of this controversy in the article. Anyone who holds an account on Fandom could check through the history and diffs, for any revision since 2019 that would indicate someone tried to add information about the undersea cable or the alleged row.