Is it possible that I can be seeing progress with my 'working sets', yet my 1RM is not improving?

I'm about to the end of WBB 1.1, and I've put on about 14 pounds, and people have noticed. That's all fine and well. But.... My bench press max is not improving. My working sets have improved, but my best 1RM was on Feb 12, and I haven't been able to move that number since that day. (I tried once 3 wks ago, and again last night).

Normal, or unusual?