Tracked 48 hours not turning up

Hi there! I was just wondering how common it is for a tracked 48hrs item to take longer than 6 days to turn up?

Before anyone says, yes I am aware the 48 hours is an "aim" and that there could be delays, but I ordered an item from Ebay which lasted updated as "accepted by parcelshop" on the 5th of May. There have been no updates since and I am worried that it either has been lost or something has happened?

I have obviously contacted the seller and thankfully they are looking into this for me. I am hoping that it is on the way and just for some reason hasn't been tracked, but I just wanted to check if this is common/whether I should be concerned. I'm more used to Inpost and Evri now when shopping online, both of which seem to be much better at tracking and delivery times so far!

It's also worth mentioning the item is travelling pretty much the length of the country, so again I understand that there might be delays but just the lack of information from the tracking number is concerning.

Any advice woud be great, thanks!