I was accumulating civics in an offline (region) game. I had just reached stage 2 and was harvesting trees. I look down and all of my civics were completely gone.

I went to the statistics and it said I was only generating 280 and there was no expenditures. I went back to my civics-producing city and within seconds I had accumulated over 2k, which was normal.

It is strange to suddenly lose all of a resource while the game was idle for 5 minutes.