Cannot complete Ritual – final altar won't activate even before map fully cleared

During a Ritual encounter, I was unable to activate the final ritual altar (located on the boss) even before fully clearing the map. I intentionally rushed straight to the boss ritual to maximize Tribute, but the ritual activation prompt never appeared. I then went back and activated the other 3 remaining rituals and fully cleared the map (0 monsters remaining), but the boss ritual still remained inactive.

Steps to Reproduce:
Enter a map with Rituals and multiple influences active.

Rush to the boss area and attempt to activate the final ritual.

Observe that the altar is not interactable.

Activate the other rituals and fully clear the map.

The boss ritual altar remains inactive even at "0 monsters remain".

Expected Result:
The final ritual altar should be activatable either after killing the boss or after clearing all monsters.

Actual Result:
The altar on the boss remains unactivatable, and the Ritual cannot be completed or rewarded.

Additional Info:
Map: Toxic Sewer

Monster Level: 83

League: Mercenaries

Server Realm: Frankfurt (EU)

Map Status: 0 monsters remaining

Influences Active:

Wildwood

Eater of Worlds Influence

Originator's Memory Influence

Mission: Einhar, Beastmaster – marked as complete

Issue: Ritual altar on boss never became active

Screenshot: [Removed by Support]