Hide Backend enable/disable is inverted

Hi guys,
I’m noticing on one of my sites that the ‘enable hide backend’ feature is inverted with the application of the rules in .htaccess.

For example if I have the checkbox ‘ticked’ to have it ‘enabled’ it actually REMOVES the rules from the .htaccess file.
And vice versa.

Any ideas how I can reset this? I’ve tried manually deleting the rules from my .htaccess and saving with various combinations but not sure what’s going on.

Cheers!