Hi tullio0106,
Thank you for contacting us!
We have tested the Smart-Multiline-Text-Box component and it works as it should.
Maybe you can share a code example with us that reproduces your issue in order to be able to give a solution for it.
One thing I strongly advise you is to check if you have included all the necessary scripts and styles for the component.
Please, do not hesitate to contact us if you have any additional questions.
Best regards,
Yavor Dashev
Smart UI Team