We were at the final boss phase during the Glassway grandmaster and I was kicked due to inactivity. We were past the 45 mins and lost our revives. I died and was viewing one of my other fireteam members and then was kicked due to inactivity about 30 secs before they killed the boss. I think you should review the qualifications being kicked. Now I have to run the whole thing over again as my other 2 fireteam members got credit for the GM when I didn't.
How’s this possible? GM nightfalls are not match made content and didn’t think you could be kicked for inactivity. You can have players in raids dead the entire fight and zero issues of being removed due to inactivity. It’s anecdotal but I’ve never personally been kicked for inactivity in content that isn’t match made.