No fix for disappearing raid keys just yet.
Bungie’s Destiny 2 recently received a hotfix which addressed a number of issues but some of the major fixes you’re looking for might be missing.
One of the fixes included an object in the Leviathan raid receiving an “unintended amount” of damage from the Exotic Wardcliff Coil. Another involved players not receiving the Linear Fusion Rifle Man O’ War as a quest reward if their weapon inventory is full. In such cases, the weapon would go to the Postmaster but this wasn’t happening either. After the hotfix, players can collect the Man O’ War from Asher Mir.
The hotfix also addressed a “rare memory leak” that would cause matchmaking to crash. Whether this is the fix to make the Competitive Crucible playlist more balanced in terms of skill rating hasn’t been confirmed.
Other issues like raid keys randomly disappearing from characters that played the raid whenever starting a new character also haven’t been addressed. We’ll just have to wait for more information in the meantime so stay tuned.