Comment by jandrewrogers

A major issue is that the US manufacturers cannot keep up with demand even as they scale up production capacity. The current order backlog of approved foreign military sales of US weapons systems is approaching $1T and growing faster than they can fill the orders.

This is creating secondary fallout as the orders from various countries get re-prioritized. It is not strictly first-come, first-served order fulfillment; you can find your order pushed back in the queue for reasons.