I’m curious as to how the 20380/385 need upgrades. American observers typically characterize Russian ships as better armed than their American counterparts.
There are problems with the air defense system, and the radar on the traditional 20380 mast. The new IBMK introduces an extremely expensive new radar, but it's unclear whether it resolves the issue. Using the Puma radar from the gun turret for the SAM actually works, but leaves the gun without guidance. The AK-630s have also been reported to have accuracy issues. There's also an issue with the Paket-NK system where because the anti-torpedoes come in factory sealed launch tubes, reloading them at sea is basically impossible, it takes serious equipment. The system could easily be re-designed to have fixed launch tubes with the torpedoes loaded into them. Final point, the AVMF badly needs a modern ASW kit for both rotary and fixed wing. Without a modern ASW helo, the 20380s will always be limited. None of these issues are insurmountable, and the type is still very useful and badly needed by the VMF, so the recent decision to extend the run by 10 more hulls is correct (in point of fact the VMF probably needs 30+ of them). They also need to upgrade the first 20380 to carry a SAM, and, even if the new IBMK solves the SAM guidance issue (I'd love to see some robust live-fire exercises against complex targets), the 6 older 20380s still need to be upgraded. Assuming they won't be replacing literally the entire mast, some radar that can do the job.
EDIT: The 20386 is bigger, more expensive, and less likely to see a production run of 30+ hulls. To top it off, at least in its original form, it carried an inferior sonar, and used up considerable space for hypothetical modules that don't exist. The cost of the ship has already gotten downright silly, and with it's size and endurance it's a light frigate not a corvette, putting it in the niche of the 22350, which completely outperforms it.