This entry for the Flind correctly lists the longbow attack as +6 to hit with a +2 damage modifier.
The entry for the Flind linked from the Encounter Builder needs to be fixed. From a design perspective, it would probably be better if both listings pulled the stat data from the same source so that the chance for transcription errors would be minimized.
For some reason, D&D Beyond appears to have multiple copies of the same monster stat blocks and these may differ.
Using the Flind as an example (from Mordenkains Monsters of the Multiverse).
The link from the encounter builder is:
https://www.dndbeyond.com/monsters/2560814-flind
In this stat block the longbow attack is listed with a +4 to hit and no damage modifier. The +2 dex has been left out.
The entry from MMotM is at:
https://www.dndbeyond.com/sources/motm/bestiary-ek#Flind
This entry for the Flind correctly lists the longbow attack as +6 to hit with a +2 damage modifier.
The entry for the Flind linked from the Encounter Builder needs to be fixed. From a design perspective, it would probably be better if both listings pulled the stat data from the same source so that the chance for transcription errors would be minimized.
Fixed - thanks!