I've never used used this header before and if I'm not misunderstanding the problem completely (it happens) I have 2 suggestions.
Firstly - are you sure you're using the 'Chunking Threshold' preference option correctly? you say you set it to '1' - I did a search and found an old post on this forum and essentially it states
indicates the threshold chunking attribute needs to be set as
- setting it to 0 disables chunking - setting it to a positive value disables chunking for requests that are larger than the set value..
so this only works correctly for chunked responses IF your response chunks are <1.....not the way I would've implemented this functionality - but still - it appears you need to an integer value that is greater than the size of your responses.
Next - if that doesnt do anything - I'd re-execute the request within readyapi! whilst proxying with fiddler to see exactly whats going on with the traffic
I'd then do the same - but this time - I'd proxy the readyapi! traffic via fiddler - then I'd compare the fiddler results between postman and readyapi! focusing on the RAW requests and responses along with the headers.
That's all I've got I'm afraid - but if were you - that's where I'd start from.....