This issue was solved after release of 7.0.10, so either wait some days until v7.0.11 is released (see parallel thread about last testing of that version) or install one of the latest v7.0.11-rc testing versions (don’t confuse with the nightly, which are a preparation for v8).
link to the underlying gitlab issue: adding a no-connect to an unneeded hierarchical pin produces additional ERCs (#16397) · Issues · KiCad / KiCad Source Code / kicad · GitLab