Platform, device and operation system
Android, Samsung S9
What were you expecting to happen, and what actually happened
When you equip 2x rings, ex 2x Firewalker Rings, 2x Runic Rings, 2x Bone Rings, etc - they should count as 2 separate items for Set bonuses. Currently, if you only have, say, 2x Runic Rings, you do not get the 2 piece Runic Set bonus.
How often does this happen? When did it begin happening?
Constant. Patch 0.37 
Steps to make it happen again
See steps above.
Would assume this is intended to encourage use of 2 different rings without restricting it to have to be 2 different rings. Gems of War is the same way where you can use multiple of the same in your team, but it does not give you the bonus for using X number of a type for those multiple repeats.
It’s a valid remark, I can also see the logical argument for it - though in GoW team setups have 4 instead of 2 slots, and are a lot more gameplay impacting - your skills and team are 100% of your chances of winning a match Two of the same ring here has much, much less impact.
Also given how most games handle equipment sets and rings in general, plus how it shows equipment slots in the Equipment menu (just one more on the list, no different from a necklace), it seems contra-natura and might confuse players.
Ether way, having the answer whether it is or not intended would be welcome!
Hey all,
This is currently intended.
I have passed this feedback on though, but at this stage it is intended that a set would be one of each type of item with any free slots allowing the player to equip any other preferred items.
I’ll pop this in feedback too, just in case anyone else wants to discuss this further or share any other feedback!
Jeto - Support Human 
Thanks for the reply!
I agree with the OP and it’s disappointing that I can equip 2 rings but only get acknowledgement for 1. Please change this.
I understand the confusion and wrestled with it myself as well. But, as I started thinking on it more, I noticed there are only 6 items of each set available to obtain. There is a max set bonus of 6/6. If you could equip 2 rings from the same set and have the second count as an additional item, wouldn’t that put you at a possible 7/6 equipped items? The current implementation seems intentional to me.