Yes, view identity as the group of people you identify with. It's a cross section of race/gender/social class/political party/geography/etc... "Defund the FBI" is just a reaction of a specific identity group -- largely the same group that hated people saying Defund the Police, fought for Blue Lives Matter, etc...
I view them as different in that this is about your personal identity. An example, is if a Republican Governor commits a crime -- should I care? Not really, it doesn't change the party platform. Maybe a minor impact associated with their chance at re-election. But when your identity is caught up with party, now you start to defend the governer purely because of their party. It's not simply a party affiliation, but your identity.
This is much larger and intractable than partisanship.
I realize that, but it’s a redefinition that makes it very challenging for people engaging in fleeting internet conversations to follow the thread.
Identity politics and partisanship have fairly well defined meanings within political discourse, and so when you say “identity is the problem” the assumption for many people is that you’re talking about issues like BLM, trans issues, etc.