I just encountered an issue with managed speed apparently changing mid-cruise on the A321 IAE, v.   I had stepped away from the PC to make dinner, and popped back into the room to check to make sure I wasn't flying into a thunderstorm - I wasn't, but I noticed that the a/c was pitched up about 10 degrees and the speed tape was just about down into the yellow hatch.  Pushing the thrust levers into TOGA didn't seem to be fixing the situation so I dialed the FCU altitude window fr