DHL ship to East Midlands from China for UK and Europe deliveries, its the Europe Hub.
They ship in a bulk Airwaybill, so you won't see any updates on DHL website tracking until the bulk pallet arrives at EMA. Once it has arrived and each parcel has been scanned your tracking will update.
Once you have the Departed Facility... from China it takes three working days to be cleared customs and scanned into the UK.
Typically once scanned into EMA, it ships out to your local hub and onto you same day. I have received many DJI deliveries from China and they always follow that pattern.
I import equipment from Japan and use DHL for these, once shipping clears customs in the Far East I make a declaration to HM Customs as to the contents and intended use of the equipment while it is in transit. It is very rare for this to hang up. Those items that were 'stuck' were probably not waiting for customs at all and were just backlogged. Thats not to say HMRC didn't randomly pick a consignment to check, on the whole the process is very efficent & DHL are pretty good at it.
We can find at least 5 known mother waybill pallets for the EU sent by DJI that didnt clear customs in China and ALL had east midlands customs clearing. Scaling well over a week in timeframe. Even ones destined for Germany were flown to EMA then back out after clearance. That added 3-5 working days to delivery.
They weren't "stuck", they were waiting for customs as DHL themselves confirmed along with the tracking for the mother and child loads - no customs was performed in China as can be seen from the tracking.
Possibly DHL were just caught out by a huge increase in load. Some peoples went to Hong Kong and elsewhere for customs, some went to europe without that stage.