Very weird problem diesel leak

[makemine205]

My 205 lucas diesel pump developed a leak around winter 2020, a small drip from the rear . When the engine ran and warmed up it ceased dripping !
Fast forward , to now and its not leaking as much because of warmer weather . BUT i decided to call into a diesel repair shop and had the technician come out and look at the engine /pump.
There was still a very slight wetness underneath the pump , almost nothing. When i asked him about other vehicles he said he had many people with different vehicles this winter (2020) with the exact same fault !!!!,
and he was at a loss to explain this problem.
Has anyone in UK experienced this strange fault , could it be something to do with the diesel fuel chemistry, has something been done to it or an omission ?.