Its not a 3rd party airport, its the basic built-in stansted, yesterday i had an add-on pack for it enabled but not today.
I have flown into here many times in all planes from the 152 up to the CJ4, including the Spitfire (but not ILS) Usually ILS works ok but not today - yesterday i now know was my fault for being too fast. Today I intercepted at about 170-180 and at 500’ warning I was still at about 120-130 i usually land the CJ4 at around 100 I think