When a substitute response is given, although it does not address the main issue, is called?

Solution 1:

A sop.

sop [noun] [C; usually singular] [connotation of disapproval]

something of little importance or value that is offered to stop complaints or unhappiness:

  • Critics see the increase in defense spending as a sop to the armed forces rather than an improvement of national security.

[Cambridge Dictionary]