Tried the orig SLAM in both TOO and PP mode, in both cases the missile acted as intended. But the SLAM-ER version is bugged somehow. In both cases (too and PP) the missile suddenly (after a few miles of normal flight) decides to perform "circle change flight" (360° left turn followed by 360° right turn and then again and again). I tried adding STPs with a similar result. (all this was tested in the missioneditor, fresh mission with 3 waypoints for the f18).
Then i tested it again, but only set 1 waypoint in the mission editor for the F18 this time, and suddenly the missile performed exactly how it should. But once i have e.g. 3 wypts, and i set my TOO to wypt 3 e.g., the missile wouldn't fly correctly and did the "circular change flight" thing. I read Chucks guide on them, watched multiple tutorials and i did everything as supposed and also i remembering using them about a year ago with no problems at all. So its almost certainly no user error.