Sorry for asking in English and short sentences, hope it's understandable.
TV brand: Panasonic
Instruction page: https://www.kpn.com/televisie/installeren/afstandsbediening/instellen.htm
Tried with the first shown remote control on that page.
Used the quick code 5 and found a code the TV works with (on/off, volume).
After confirming with OK button the red light blinked 2x like described but after that only on/off for TV works but no volume control (+/- mute).
Any idea for reason?