I just did a quick experiment. I disconnected the AEs (ibrights) and tested it with the HLs on and fogs on - no inactive selflevel suspension message. I did not put the stock ones in. I just disconnected the AEs at the terminals.

I tried it several times and turning the X on and off too. Couldn't get it to give me the ISS message.

So, I can safely say it has SOMETHING to do with the LED AEs but can't 100% attribute the problem to it only because - I have my AEs wired to a 12v source. So, my AEs are on whenever there's power and wired different than stock.

I don't have the time right now to experiment more but, at least in my case, it seems its as gruf said - especially if he has stock wiring and all he did was replace the bulbs.

It's concerning that you don't get errors/problems right away - only after some time has passed. Correction, at least for me and StartX5, there was the AE blinking on the driver side HL on powerup.