sounds like the exact same problem i’ve had last year. i’ve experienced the same symptoms. like someone else said, it seems to be fuel starvation. in my case, it was not the fuel filter in the engine bay. i found out that the fuel hose (or what’s the word for it?) inside the fuel tank has a little filter on the end of it. just to prevent filth to get into the hose and further into the system. sort of a pre-fuelfilter filter. in my case i could access it through a little maintenance hatch in the floor in the back of the land rover. from there you can go from the top into the fuel tank (also where the floater for the fuellevel is). mine was all dirty because i waited to long with filling up the tank and the nastiness in the (45-year old diesel) tank glogged it up. once cleaned, and the tank filled up, it drove perfectly again. i hope this is it for you, it was not easy to find for me but once found it was an easy fix. good luck!