`autocmd WinEnter` breaks Neovim's diff mode

[dmyTRUEk]

This line from config breaks Neovim's diff mode (nvim -d file1 file2):

autocmd WinEnter * silent! lua require('scrollbar').show()

Additional info:

• Scrollbar version (commit's hash): bc97c132e8367efecb2ecb937d385e7dc04eb5a1,
• Neovim version: v0.8.2,
• Shell: zsh,
• Terminal emulator: alacritty,
• OS: Arch Linux.

Expected:

Got: