Bug Report ID: #19566582 - Abyss conversion message but no Abyss map appears (Sealed Vault)

I just completed a Deadly map with a special Sanguine boss. During the map, I received an on-screen notification indicating that a connected map was converted into an Abyss map (message wording similar to “A connected map has been overrun by the Abyss” — exact text may vary).

However, after completing the map, no connected Abyss map could be found on the Atlas. There was no visible Abyss indicator, no conversion, and no affected connected map.

For comparison: I previously received the same Abyss conversion message while inside a Tower, and in that case the connected Abyss map did appear correctly on the Atlas.

This makes it seem like the Abyss conversion message is being triggered correctly, but the actual map conversion sometimes fails to apply or fails to display.

Map name: Sealed Vault
Context: Deadly map, special Sanguine boss