Bug: Keyframes lock on copy-and-pasted layers

[ryans96600462]

When using a layer that has been copied and pasted into a comp -- in my case, from one comp into another, or from a Premiere timeline into an After Effects comp -- the keyframes become "locked". They aren't marked as locked, but they can't be selected, moved, or manipulated in the Curve Editor. They can be changed by moving the playhead over the keyframe and adjusting the parameter under the Layer Controls, but only then. The exact same assets when dragged into a comp from the Project panel do not have this issue, and this issue is repeatable and constant for me. Version 18.2.1 build 8. Windows machine. This issue is sometimes but not always is accompanied by visual glitches (especially in Graph Editor -- panel pieces disappear to blackness) and/or crashes. Anybody else encounter this?

[ryans96600462]

Update to add: Often accompanied by error message "Attempt to get an item address from a position outside of list length (27::15)"