ZTNA : Traffic denied because of mismatch HTTP host

[Stephan_s]

Dear all,

from time to time I get complaints about not working ZTNA provided Websites. It mostly affects onSite users only and the corresponding Error message in the ZTNA Traffic - log is like that:

Traffic denied because of mismatch HTTP host:[URL] with vhost(name/hostname:[access-proxy-virtual-host]/[URL])

The [Brackets] were placed by me to hide internal information. The URLs are identical and the access-proxy-virtual-host is existing.
After a while its working again by itself. I got the feeling that its maybe always happening if I do configuration changes on the firewall. But today I worked on IPSec and SSL VPN which should not be related to ZTNA. So maybe its connected, maybe not.

Did someone have the same issue and has an idea how to fix it?

best stephan

[Stephan_s]

Additional Information:
Fortigate 200E with version 7.2.7