Hey guys.
I deployed TeamSpeak server 3.4.0 on my server today, then I ran into a problem.
After some configeration I decided to make all channel looks better by changing their icon. So I uploaded them and set them via edit channel, everything seems good from my side, then all my friends conneted to this server told me that there is nothing on their screen, and all their pages are oddly "flashing", Im not sure what that means since I dont have access to their pc. I serched it on google and learned icons , avatars, files using the same port to transfer, it became more confusing since some of us already have avatars on the server that every other one can see, also I tried upload/download file via client, it also worked.

My server is running Cent OS 7.5, here is a list of everything I tried, but all of them failed to fix the problem:

Disable server firewall

restart teamspeak service on server

adjust server sitting regards file transfer

If anyone know how to fix the problem , please help.

Thank you all so much!