Drop chances of played class

Seems the drop rate for the class I'm playing is favoring classes I'm not playing.

Yellow and Uniques are 2/3 for class I'm not playing, is this a bug?

Not a bug. Every class can use any non-ascendency skill as long as you wield the correct weapon and have enough stats to use the item. Having drops that focuses on the current starting class would be very harmful for choises. Don't stress about uniques though. Most uniques are either bad or seem very bad unless you build very speciaifally around thm. If you don't trade salvage them for chance shards (or if they have low value). Then use chance orb on bases that could yield uniques for your build :).

All globa-pool uniques can drop for any starting class. It is natural that you get something not for the skill you picked since there are so many skills.

Make sure you use two different weapon sets and chances are larger that you get something useful :) Very often two skills from different "classes" can synergize very well. Remember it is only your chosen stat that limits you from using them (outside weapon type).