I'm new to the game (latest patch btw). I found out through trial and error that strategic resources aren't mined every turn like normal ones, but seem to come in a "one shot deal" where their quantity is mined only once. However, in various attempts of playing around, by building another improvement on the strategic resource (firaxite for instance) and then cancelling before complete and rebuilding the strategic resource mine, it seems I can get a "one time shot" of the resource again.
It hasn't always been successful. For instance in one series of attempts where I did this across my empire my firaxite went negative. But I think I know what I did wrong in that case, and in most attempts it seems to work.
This does seem like a bizarre way to get resources, however, and I've wondered if I've simply stumbled upon a bug and am exploiting said bug inadvertently, or if there is some better way at getting these resources and I'm simply doing it wrong. Off the top of my head I doubt that I found a bug, because what I'm doing would be the first thing that legions of "bug exploiters" would have thought of, and knowledge of this should have been out there long ago.
Questions:
1) What is the intended mechanic for these strategic resources? One shot deal? Multiple shot deal? Etc.
2) If one shot, then have I found a bug?
3) If multiple shot, am I doing it correctly or is there a better way?
Thanks.