Legacy character Monk class martial arts die has scaled up based on the 2024 rules and there is no option to switch back.

e.g. Monk weapon attacks should have 1d6+_ at level 5, not 1d8+_

https://www.dndbeyond.com/characters/131309779

I got the same problem

https://www.dndbeyond.com/characters/108823365

We need a toggle to turn off 2024 content.

This is a known issue. See here:

https://www.dndbeyond.com/forums/d-d-beyond-general/bugs-support/204813-players-handbook-issues-and-support-thread

Under Monk it says:

Martial Arts. We don't have a method of disambiguating the Martial Arts granted by the 2014 Monk and the one from the 2024 Monk. As such, all Monks will temporarily match the 2024 Monk's Martial Arts Die until we’re able to fix this.