It has nothing to do with Brexit they're local elections, the only real link is that Brexiteers are so disgusted by the Conservatives on the national stage that they boycotted or spoiled ballots with Brexit messages.
Also to call the Conservatives hard Brexit is laughable. Theresa May has been trying to force through a new treaty to keep us an EU vassal state and is now in talks with Labour to soften her stance even more.
Wait for the EU elections, the only politician Brexiteers trust at this stage is Nigel Farage.