Hey IPA, funny you mention this because I had a similar thing happen to my almost identical IPA just recently. When I say almost identical I mean my OG was 1.060, my FG was 1.012 and I pitched the same 1056 yeast.
My IPA's (which is in the secondary now) airlock had activity until day 7 and then stopped by that night. I had my temp controller set to 63°. On day 12 the FG was at 1.012 and once I put the lid on and put it back into my ferm chamber the airlock started up again! I'm sure it was due to some out-gassing since I moved it around.
Anyway, at day 12 it was still at 1.012 so I racked to my secondary and will dry hop in a few days for 5 days to and then cold crash for 2 days then bottle.