I'm using a web scenario with two variables:

{user}=username
{password}=password

When I create this template (Web_check_template) and apply to a host everything works as expected. Here's the failed case:

Create another template (Customer_Server_Template), then add the Web_check_template with the web scenario as a linked template. Again, things will work fine - until you add a host to the customer server template.

When the host is added to Customer_Server_Template, the web check begins checking and the password variable sent is missing the last letter (passwor). I validated this via the debug log output (not attached, was several days ago).

Once the host is added to the template, the web scenario fails. However, modifying the original template (which still shows the correct password variable) to simply change the password and then change it back corrects the issue, and the webcheck begins succeeding again for the new host- until another new host is added. Note: All existing hosts continue to function at all times - it's only the newly added host that fails.