It is easy to get paranoid when you are looking for a specific drop. Spawn rates and drops are just simply random. I have been crafting a lot of luminescence this week and using my mermaid scales. Yesterday I could not find mermaid scales in any of the usual places. If we needed scales for this quest, there would be about 50 posts saying S8 had turned off the mermaid scales to make us use gems. Lol. But today, all my wells and ponds are dropping scales like crazy. Some days, certain drops are rare. Then they cycle back around in the next day or so.
I know some players are convinced that there is a conspiracy about drops or spawns. Oh well.