Are all affix combinations possible drops?

[Res]

Version 1.1.7.0 added something called “affix bias”. Certain items are more likely to come with affixes that suit them.

@Zantai

All gear is now more likely to roll Magic and Rare affixes with damage types appropriate to it (ex. a Fire scepter will be significantly more likely to roll affixes with Fire damage, or a Pet Ring rolling affixes with pet bonuses).

Maybe this is what you’re witnessing. All combinations are still possible, but some are more rare.
Sidenote: I never liked this change.