Despite
@Graculus provided links, everything I can see revolves around vehicles arriving a port of departure without the correct paperwork. That is not a Dover issue.
The biggest single cause of delay for fish products seem to be that exporters and hauliers are struggling to get the correct paperwork which is firmly under the control of the Scottish Government.
DFDS hasn't got its system in order, and they admit it, I believe they are the biggest groupage operator for fish out of Scotland
Vet/health checks are simply a clusterfuck, Scottish Government responsible for that
Exporters are not getting their paperwork correct.
These are the primary reasons lorries are being delayed getting across the Channel.
HMG has been quite clear for over a year on the changingg requirements, Every operator in the UK has been updated regularly and with great clarity by HMG.
@Graculus the problems at Dover are caused by people not preparing their shit. The Scottish Government has not done its part.