Think it's a worldwide thing - here in AUS, it took 3 weeks to have a parcel delivered 12km away in the same city! Currently, our postal service is attempting to process in excess of 2 million parcels/letters every day - this is even greater than what they usually process during our busy Christmas period.
I had 2 parcels arrive from the US in the past month - both via FedEx - and they took a little longer than usual: 10 days vs the usual 5, again, it was delayed in Melbourne which is our largest mail/delivery hub.
Yet I'm still waiting on a parcel sent from Portugal - has been over 6 weeks. Given that anything we send from AUS to Portgual is going by seamail, this is not at all surprising, when you consider that due to our borders being closed, the passenger aircraft that usually arrive and depart (and also carry mail deliveries) aren't currently in operation.
I had a seller in Germany cancel an order - they were suddenly no longer accepting post to AUS, the day before, however, had been fine.
And I posted off 3 parcels on April 28 to the UK, Russia and Denmark. Guess what happened? The 29th saw new postal details take hold and those parcels are currently awaiting their international leg. Unfortunately, the Russian parcel now must be sent via seamail - anywhere up to 30 days, and there's absolutely nothing I can do to make changes right now. The only "return to sender" mail being processed, are those parcels/letters that have had their deliveries suspended completely. Everything else is still going out, but delivery times right now are anyone's guess.
Hope it arrives in good time, but these are crazy times and totally out of anyone's control - we just have to sit tight and celebrate when our packages eventually arrive.