I changed my username from Lyc4nr0c to Flowight yesterday, but since then I can't play multiplayer or in a realm. On the minecraft site my new username is visible, but in minecraft it self it still says Lyc4nr0c. It itsn't my wifi's fault, because the wifi on my phone and chromebook is good, and so is the wifi on my laptop which I'm playing minecraft on.

Please solve this! I dont know what to do!

Thank you in advance