Hey,
delete your XIM Config and create a brand new one. Dont change anything in it until inputs are registered in the game again. That way we can rule out accidental config changes that caused this.
Next plug a PS4 v2 controller into port 3 of your XIM. The DualSense wont work, its not XIM Apex compatible. After that make sure you play the PS4 version of a game. XIM Apex is not compatible with PS5 games, for those you must work one of the various PS5 workarounds described in the forum. At last check your ingame settings. Those must match the required ingame settings from the XIM website.
If it still doesnt work, use a different USB cable for the controller. It has a to be a data cable, so no charging only cable.