Hello @Bugra Keskin Thank you for posting this concern on this community space. I have read your whole case scenario description and I just wanted to ask few questions down below:
- -When you were referring to Internal websites... Are you talking about intranet websites that you own?
- -How are those internal websites being accessed via S2S VPN between Azure and on-premises or ExpressRoute circuit?
- -Is there any Firewall in the middle of the website server and your end users?
- -When did this stop working properly?
- -Are the end users computers using the same OS version? Looking forward to your feedback, Cheers, Please "Accept the answer" if the information helped you. This will help us and others in the community as well.