I've searched, and I only found reports of the Firebead and Tethtoril bug in Candlekeep.
I've tried in 3 saved games, and Firebead no longer gives the quest to fetch him a copy of History of the Fateful Coin in Beregost.
When you go into his house, all he says is: "Ah, next time you pass through Candlekeep, you should read the "History of the Bell in the Depths." It is an old favorite of mine that I'm sure you would like."
This also means that there's no way to get the scroll case anymore.
[EDIT] If you have Shadowkeeper, this can be fixed by deleting the Global variable "TALKEDTOFIREBEAD" or setting it to 0.
If you don't have Shadowkeeper, you can also type this in the console: