3.5.2 breaks unmounting components in keyed each blocks

[btk5h]

REPL 3.5.2 (breaks)
REPL 3.5.1 (working)

The code seems to break when components are unmounted inside a keyed each block. The bug does not occur if you replace <Thing value={thing}/> with [{thing}] inside the keyed each block, or if you remove the keyed each block entirely.

Curiously, the keyed each block also seems to break the behavior of preceding each blocks. Notice that the incorrect component is removed in the first unkeyed each block.