I have the same problem! I’ve tried numerous ILS approaches into EGLL 9L, frequencies & approach coarse correctly set on both sides, nav system set to radio, dh set on both sides, both autopilots set to CMD, the ILS/LOC lights on, and showing as armed or active on the annunciator… and the plane just flies through the approach path regardless of how shallow the intercept is. It was a little ‘flakey’ on release, but it would work… now it just seems completely broken for me. I keep thinking it must be something that I’m stupidly missing…. But can’t for the life of me figure out what. I haven’t had the gps fitted so it can’t be that in the wrong mode. I had installed the TriStar, but have now tried it streamed and had exactly the same issue. This is in FS2024.