I discovered this strange glitch while playing on my XBox Series X. Having acquired the new Idunn’s Heart ability, which is super cool, Eivor will start to glow yellow when wearing the complete Dublin Champion set, as if the effect of Indunn’s Heart stays active, even when no healing is taking place. This has apparently happened only when equipping the complete set, and I have not seen it occur with any other set... only the Dublin Champion. In the video below, please note that I have modded the appearance of the Dublin Champion set to look more like the Black Raven set.
What is odd is that when Eivor gets hurt, the actual ability of Indunn’s Heart kicks in and the glowing stops, but if I switch out an armor piece and then equip the previous piece again, the glowing starts up again. At this time, I have found that restarting the game will cause the glowing to stop, but I will keep an eye out if it happens again. Regardless, this is a very strange but visually cool glitch... it reminds me of going into an Isu tomb in AC Origins as Bayek and standing on the teleportation platform.