It can be caused by a multitude of reasons. The product will have detailed specifications, which are most likely only supplied by a single vendor; they can't visit the local paint manufacturer for replacement product. In addition to natural disasters, you also have supply chain and transportation issues, with numerous ships sitting anchored awaiting berths and more locally, rail and truck delays due to manpower shortages.
At any time, products can be delayed in arrival, as they are sitting on a ship, train or truck somewhere in the World.
Commodity restraints are ongoing and they change every week.