Non editable posts - TinyMCE special characters issue 'C2A0'

[katazina]

Related ticket: #35890

Same issue, many "spaces" before text, wpautop is off.

But I have the latest WP and the issue still exists.
This is the exact character which causes the problem: C2A0

In mysql I can replace it and check if it's there:

select replace(post_content, UNHEX('C2A0'), '++++++') from wp_57_posts where ID = 5545448\G

[katazina]

spec chars

[azaozz]

This sounds like a duplicate of #38294.