PAC Server issues in China - error 504 Gateway timeout

we have some issues at one of our locations in mainland China.
Locations has two IPSec tunnels opened and the PAC file is fetched via IPSec / via the Public Services Edges.

Customer now often gets http 504 as return code, almost 50% depending on the used PAC Server.
For Germany, we have the same setup (PAC files fetched via IPSec) and we see 100% success rate.

Obviously “something” blocks the traffic between the PSE and the PAC server.


Related case number: 02602820
Best regards