Ussd change to call

For some reason my phone can't dial any ussd code more than 5 digits. For example: I could dial *888# but can not dial *5050#. When I dial ussd code more than 5 digits and press the call button it will calling to that ussd code. I do some research but I don't find any questions like mine, but sth like make a call but changing to ussd running, opposite of my problem. My phone is LG X4+ ( yes not a popular phone at all ) i hope someone could help me