Because it's bothering me ...
This is from Legacy of the Crystal Shard (which is set in 1485 DR, during the Sundering, and is a 4e/5e transitional adventure):
House of the Triad: "Bryn Shander's largest place of worship, and the only one that truly deserves to be called a temple ... When it was first built, it honored the three gods known as the Triad: Tyr, the god of justice; Torm, the god of duty and loyalty; and Ilmater, the god of endurance in the face of suffering. Tyr is said to be dead, though he still has a handful of followers in town, and the holy days most commonly celebrated in the temple are those of Ilmater. The promise of divine aid for those who endure suffering appeals to the people of Ten-Towns."
Shrine of Amaunator: "... a modest gathering place for worshipers of the god of the sun. Considering that the sun vanishes for two months at a time every winter, it's a wonder that Amaunator has any worshipers at all in Icewind Dale. The priest who established the shrine, a retired adventuring cleric from Cormyr named Mithann ... speaks a powerful message of hope and rebirth. She calls Amaunator by old names - the Morninglord and the Glory of Dawn - that evoke a different image from that of the stern, rigid sun god who is worshiped farther south."
[As an aside, it specifically states that Mithann was a former adventuring companion of the famous paladin Isteval, who calls Daggerford home and was one of the big names in the Sundering series, making appearances in Ghosts of Dragonspear Castle, Scourge of the Sword Coast, and The Rise of Tiamat, among other things.]
This is from Storm King's Thunder, which takes place sometime after 1489 DR:
House of the Triad: "Bryn Shander's largest place of worship, the only one that truly deserves to be called a temple ... It honors the three gods known as the Triad: Tyr, the god of justice; Torm, the god of courage and self-sacrifice; and Ilmater, the god of endurance in the face of suffering. The temple is attended and maintained by visiting priests and acolytes from Neverwinter and Waterdeep, who usually stay no more than two years ... At present, the temple is home to a priest of Torm from Neverwinter named Dellvon Ludwig and his faithful friend, Sirac of Suzail."
Mithann and her shrine to Amaunator don't get a mention.
Finally, this is from Rime of the Frostmaiden, which is set in between the above two adventures in the timeline:
House of the Morninglord: "... this modest converted house serves as a gathering place for worshipers of Amaunator, a god of the sun known to take both male and female forms. A retired adventurer named Mishann runs the shrine and aspires to see the sun regain its rightful place in the sky over Icewind Dale. She calls Amaunator 'the Morninglord', a name that southerners use to describe Lathander, a god of the dawn and rebirth. Mishann views Lathander as a usurper of Amaunator's light and doesn't like it when people confuse the two deities."
The House of the Triad doesn't get a mention, although, because it appears in adventures set both before and after Rime, it surely must exist. (To be fair, the entry for each of the Ten-Towns in Rime is noticeably shorter what they get in the Legacy of the Crystal Shard Campaign Guide.)