I use the Signal app on my iOS devices and while connected to our home network, I can receive messages just fine but when trying to view/download any attachments, they won't load. Typically, I find this is caused by SSL/TLS decryption and I can usually see which domain(s) are being utilized under 'Web filter', but I'm not seeing anything related to the Signal app. The only thing I see is under 'SSL/TLS inspections' the domain textsecure-service.whispersystems.org being accessed. I added that to the Local TLS exclusion list but the attachments still won't load. Upon disconnecting from my network and using cellular, the attachments load fine.
What other steps do you guys take to troubleshoot issues like this? I find the Sophos XG logs are a hit or miss with being able to figure out what's going on.
