Caller find me "user busy" in first call always
I am using Iphone XS and Iphone 14 Pro with both IOS 17.3.1
Every time someone tries to call me, the first dial would always say "user busy" or it automatically drops out. I have checked my settings and no call forwarding is active. Also, my network has a technical support to run diagnostics with the number i have and no issues are found. I have tried restarting my phone many times, but it still doesn't solve the problem.
I hope someone can help.
iPhone 14 Pro