WP 6.5.3 – admin sidebar permanently in collapsed mode

The admin sidebar in WordPress 6.5.3 remains permanently collapsed when using your plugin “Unique Headers” and being logged in. If I disable “Unique Headers” I can have the admin sidebar unfold and collapse again without any problem. I am using Twenty Seventeen as my theme.

Everything else seems to be okay – only switching between full mode and collapsed mode is not working for the admin sidebar. Any idea how to fix this? Thanks in advance!