Ok, this may be a MS problem but I can confirm it happens with Aruba APs. I upgraded 2 Surface Pro 3s to the latest "Creators update" version 1703, and started experiencing an issue where they will stop passing traffic even though they have a valid ip and are authenticated. They WILL work if I force the adapter to 2.4ghz, it seems specific to 5ghz/ac mode. Sometimes you can get it to work only to have it get into that state suddenly after 10 minutes or so. The tell-tale sign is the yellow ! on the adapter. I was wondering if anyone else has seen this happen? It doesn't seem to matter if its an open network / PSK / .1x auth. I've read a lot of other users having issues but no definite fix and I've tried the suggestions that are out there.