Blocking wp-login in HTACCESS has also blocked password protected pages

Unfortunately a Password Protected post uses the wp-login.php file to process the password authentication for a post. So your Apache snippet of blocking all but those specific IPs is going to apply to anything that is password protected as well.

You can get nerdy and read code. In here you can see that Post Password form’s action is set to run that data through wp-login.php?action=postpass

So that is the bad news, BUT:

I wonder if trying to open that up so that your other files in WP can access those files? (I am just purely guessing at this point)

# Block access to wp-login.php.
<Files wp-login.php>
order deny,allow
allow from 192...(ip)
allow from 192...(ip)
allow from localhost
allow from 127.0.0.1
deny from all

I hope that helps or gives you some insight!