Is ebony armor supposed to be weaker than glass when improved?

Solution 1:

I'm betting that your light armor skill is loads higher than your heavy armor skill.

The base armor on an item (that is improved with smithing) is only half of the formula - this is increased by your light or heavy armor ratings.

I'd re-compare the results when your Light and Heavy armor skills are equal.

Solution 2:

The value you see displayed in-game is modified by your skill level -- if your Light Armor skill is higher than your Heavy Armor skill, and/or you have more armor rating perks in the former than in the latter, you will see a higher rating on the glass than on the ebony; in fact, you'll see this same result on un-improved versions of both -- neither will show the base value that UESP shows, and I'll wager you see a higher rating on the glass than the ebony.