This is completely unsurprising. Under the new "free speech" regime, X has been completely deluged with antisemitic, pro-Russia, and anti-democracy propaganda. It's no wonder that advertisers don't want to be associated with that type of content.
“Goebbels was in favor of free speech for views he liked. So was Stalin. If you’re really in favor of free speech, then you’re in favor of freedom of speech for precisely the views you despise. Otherwise, you’re not in favor of free speech” Noam Chomsky