Obsidian v0.12.12 on Windows
if you type [[#
and choose a title with blank and use autocompletion, you will get an anchor with non-standard format with URLEncoded. If you change it to standard one, you can jump to proper position in Github and other viewers accepting the standard format but will fail in Obsidian.
An Example:
# Anchor Test(test)
Obsidian autocomplete: [Anchor Test test](#Anchor%20Test%20test)
Standard format accepted by Github and other viewers: [Anchor Test test](#anchor-testtest)