Hi @Zero7106! Thank you for raising the issue you encountered when joining a Hunt-A-Thon invite from others. We apologize for the inconvenience caused by this.
We recommend following the Troubleshooting Guide here to prevent such issues in the future: Troubleshooting Guide (IOS) — Monster Hunter Now Help Center
In the meantime, please also refrain from using Bluetooth-connected earphones, in case you use any, while playing the game. For more info on this, please see the announcement here.
If the issue continues, please reach out to us via in-app support for further assistance. Thank you!