We're seeing the same thing - our sandbox pushes started to succeed again about 8:30AM UTC. Seems to be resolved, hopefully it stays that way!

Looking back at our logs, it began happening for us just after 2022-01-26 00:00 UTC as well. Appears to be resolved as of about 2022-01-26 08:30 UTC.

Given the comments, and the fact that it started working again without any changes on our side, safe to say this was an issue with the APNS Sandbox service. It appears to have been resolved.

+1 also encountering this error on a seemingly simple GET request. Interestingly, when I setup a proxy (Proxyman), requests from the same device succeed, then start failing again when I turn proxying off. Suggests to me it has something to do with the network connection to our specific server (i.e. the proxy tool is masking an underlying issue). Has anyone on the thread here has success in resolving/avoiding this error? Reading the other thread that @eskimo mentions, I notice mention of the problem starting when "servers migrated to Http2". We also similarly moved to Http2 when we introduced a caching layer in front our service. Requests direct to the underlying service don't exhibit this issue, but I'm hoping we can determine a more specific cause.

+1 I'm also encountering an NSURLErrorCannotParseResponse error on a seemingly simple GET request. Interestingly, when I setup a proxy (Proxyman), requests from the same device succeed, then start failing again when I turn proxying off. Suggests to me it has something to do with the network connection to our specific server (i.e. the proxy tool is masking an underlying issue). Has anyone on the thread here had success in resolving/avoiding this error? I noted the mention of the problem starting when "servers migrated to Http2". We also similarly moved to Http2 when we introduced a caching layer in front our service. Requests direct to the underlying service don't exhibit this issue. I can raise a bug for this, but I'm hoping we can determine a more specific cause and workaround for existing deployed apps.