That looks like it has fixed it. Thanks for the quick reply.
ICSdroid Accept-Encoding: gzip compression working
I did not find a mention in the documentation and just did a quick test to check it out:
icsdroid sends the correct header and works fine with a gzipped reponse.
GET /test.ics map[Accept-Encoding:[gzip] User-Agent:[ICSdroid/1.4.2 (Android/7.1.2)] Connection:[Keep-Alive]]
Thanks for mention it here. ICSdroid uses the http lib of Android.