You can't say the savings rate goes up while also saying that increased spending via stimulus is causing inflation. You can only have one or the other. Those are at complete odds with each other.
The far more obvious explanation is that the supply side has "collapsed" and that should be obvious and the problem isn't monetary inflation, it's just in time manufacturing causing extreme bullwhip effects.
Think about car manufacturers canceling their semiconductor orders. If they hadn't done this, car prices wouldn't have risen as much as they did.
The real question is, are our car manufacturer executives stupid enough to keep canceling semiconductor orders? If yes then enjoy stagflation for years to come, if not then you will have to wait until semiconductor manufacturers catch up with the new orders.
Go one step further and bomb all car factories. You're going to see hyperinflation in used car prices.
If you are smart about it you can create money without a corresponding debt (aka printing money i.e. something the Fed isn't doing right now) and spend it on building semiconductor plants and then end up with deflation as prices of semiconductors drop, therefore using an increase in monetary supply to explain inflation will always cause problems because there are so many exceptions.
Yes, this means if Zimbabwe were to print money and use that money to support farmers it would actually get rid of its hyperinflation.