I had the option on one of the menus to lock the position and rotation of the model for AR viewing. I no longer have that option. has it been removed or relocated, or a different version of the app?
Lock position for AR
It has been moved: you now have to open the Settings dialog box and go to the Scenes page. One of the reasons for why it was moved away from that menu is that it might confuse new users, particularly if they pick it accidentally when starting, throwing them in an unexpected modal environment.
…In other words, you can pick “list of scenes…” in the same menu to get to “position model in space” which is now a button. In the next release, that menu item will be renamed to “scenes / position in space…”. I hope this should help other people that wonder where that command went.