Annoying circles and nasty sound around the character's neck

@3AKOH_B_3AKOHE Do you have mods or CC in your Mods folder? If so, do a "vanilla" test to see if a mod/CC is your problem: Drag the Mods folder to the desktop, delete the file called localthumbcache, open the game to test, and exit without saving.

I had mods, I tested as you described, but the result remains the same, these circles appear regardless of the mods. Maybe you can give me a cheat code to disable this buff/moodlet/character trait?

@3AKOH_B_3AKOHE When you're testing with an empty Mods folder, how far back are you going? Are you testing starting before the circles would have appeared in the first place, or only testing after they've appeared? It could be that the very appearance of these in the first place is mod-related.

@3AKOH_B_3AKOHE Okay! Someone else pointed me in the direction of a part of the game I've not used yet: Immortality Potions. The effect should wear off in game but might come back on travelling.

LittleMsSam's Other Mods - Immortality Potion Tweaks (orig. by Scarlet), on her own site and Curseforge, will get rid of the VFX but has other changes it makes too. The VFX part is an add-on for the mod.

Simskiller's No Annoying Immortality VFX on Mod the Sims covers only the VFX if you aren't interested in other changes.

I test, and only after they appear do I let you know that they appear even without mods.