Not a lot of known issues listed for the new patch, and “massively increased legendary drop rate” isn’t included. (Which means either Bliz doesn’t know, or it’s not considered an issue.) Here are the current Patch 2.3 Known Issues:
The Leoric’s Crown issue is amusing, since that was about the only legendary item that has been non-functional when extracted via Kanai’s Cube since the PTR started. So whatever Bliz fixed to enable it, disabled the “no double dipping” code, which prevents you from gaining the same legendary affix via wearing the item + enabling it via the Cube.
As always, programming is hard. In the meantime, if you’ve ever wanted almost 100% uptime for any ability that’s bottlenecked by cooldown reduction, hit the PTR with 2 Leoric’s helms a Flawless Royal Diamond.