Hyundai like all manufacturers frequently issue ECU updates for a lot of car systems - engine, transmission, body control ,abs, air con etc.
A lot of odd problems can be cured with these updates. It is worth asking your local dealer if there are any for your car if you are having odd problems and no one can cure it. Normally they will check for this on a service but the dealer has the ability to look it up on GSW- Hyundai's technical internet platform. it may cost but its worth it.
When you are asking for help on this forum please can you state the fault code number if you have one. It will start either P/C/B or U followed by a series of numbers. Older Hyundai's do not like a lot of Generic fault code readers and give ghost codes-/false codes. I have code readers for models up to 2014 which are genuine Hyundai stuff. The later Hyundai's are less of a problem.