[mariosipad]

[I had some internet (ISP) problems today. Some sites like this one refused to load. Seems to be fixed now.]

1 - to use .htaccess you might need the AllowOverride All statement like you have now.

2 - I would slightly change the lines you put in apache.conf, but it should work like you have it now.

<Directory "/share/Web/COPS111">
    Options FollowSymLinks MultiViews
    AllowOverride All
    Require all granted
    AuthType Basic
    AuthName "RESTRICTED AREA"
    AuthUserFile /share/Web/COPS111/.htpasswd
    Require valid-user
</Directory>

3 - to make a change in an apache config file work, apache needs to either be restarted or the config files should be reloaded. Rebooting the QNAP has the same effect.

This all probably explains (hopefully) why authentication did not work. I hope it does now.

Did I mention I hate Apache...?

Well I have the same with NGINX. For me apache usually works after a lot of
while NGINX does not.