Here is a major rock act that is going to Lebanon, a country that forbids Palestinians from owning land, from becoming citizens, from building new houses, and from many kinds of jobs. By law.
Palestinians are stuck in UNRWA camps where various terror groups fight each other, and sometimes the Lebanese army, in an atmosphere of lawlessness.
Lebanon is, by any definition, an apartheid state. Palestinians know this well and the ones who can escape to Europe, do - over 200,000 of them so far.
But I have never seen any "pro-Palestinian" group say that Lebanon should be boycotted, or punished in any way, because of how they treat Palestinians.
This is pretty good proof that when people say they are "pro-Palestinian" they really mean that they are anti-Israel.
Everyone knows this but no one likes to say it out loud.