Domestic FedEx seems to be in complete chaos at the moment. I had 2 parcels last week that were delayed by a few days just sitting in UK hubs. They eventually used these 3rd party 'same-day delivery services', which essentially means the parcels were passed on to non-FedEx drivers. In both cases the driver didn't ask for a signature and just left the parcel outside.

Another one this week just sitting at the Huntingdon hub at the moment - called them just now and was told that there's a massive backlog that they can't even keep track

I wonder if that's the case for other couriers too?