I'm not a mead maker, but I've made beer several times. Sometimes the air-lock won't appear to be active. I've seen where sometimes it takes minutes for a single bubble to form. Also, you won't see any bubbles until enough pressure builds up.

I've also had ferments that made a column of foam through the top of the air-lock. Some looked like a torrent inside the bottle, others seemed like no activity was taking place (but sugars were still turned into alcohol at the expected percentage).

The type of yeast makes a large difference, and the conditions it thrives in (temperature, food source, etc).

Since you have bubbles in the jar, activity is taking place. The one thing I do know about mead, is that patience is needed for fermenting. I look forward to seeing more of this project!