Contradictory parts of D&D Beyond: which is official?

Question

If D&D Beyond is considered an official source, how do you figure which part is official when parts of the site contradict other parts?

Example: the monster page for the gelatinous cube says:

Senses Blindsight 60 ft., Passive Perception 8

While the gelatinous cube's entry under Monster Stat Blocks in the Basic Rules says:

Senses blindsight 60 ft. (blind beyond this radius), passive Perception 8

(All monsters have mundane vision, without any range limit, by default, unless that parenthetical note is there, so one version of the cube can see someone 65 feet away with normal sight, while the other is naturally blind and can't.)

If a monster is naturally blind, it has a parenthetical note to this effect, indicating that the radius of its blindsight defines the maximum range of its perception.

Another example: the monster page for shadow says:

Skills Stealth +4

But its entry in the Basic Rules says:

Skills Stealth +4 (+6 in dim light or darkness)

(One DDB user did point out this discrepancy in the shadow's Stealth skill on the site already, in a comment on July 7, 2019; although that comment is wrong about Undead Nature, which is correctly omitted since it isn't part of the statblock.)

Answer 1

There is no official order of precedence, but you should probably trust the "book" pages over the generic listings

D&D Beyond is meant to be an accurate representation of all official 5e material, and almost all of the time it is, but as with any large project there are sometimes errors that sneak in - much as the physical books sometimes have printing errors or other problems and need to be updated by errata.

Given the way the site is put together, the content which is included as a direct representation of a specific physical book is most likely the correct transcription, and errors are more likely to have crept in in the generic aggregated databases of content. As @V2Blast points out, one factor is that the statblocks in the compendium versions are basically just text formatted to look like a statblock, and so they don't have any of the technical limitations that the generic monster database does - for instance, at the time of posting, the inability to attach ad-hoc text to the skills listing to indicate conditional modifiers like the Shadow's.

Therefore, I would trust the entries as they are given in the Monster Manual, Basic Rules, or whatever other "book" representation (essentially, URLs starting with /sources/ or /compendium/) over the generic entries. However, there's no "official" order of precedence for the site's content, as these disparate pages are all meant to agree! The standalone listings are meant to match the compendium versions, except when a newer version of the same thing (e.g. a monster statblock) is published in a newer book.

If you have an account on the site, you can report issues with the site content in the support forum. The site devs seem to be pretty good about correcting errors like this when notified.

Answer 2

I would assume that those are transcription errors on the part of DNDBeyond. The official sourcebooks should always be your primary guide for information. Stat blocks in official modules would be the only thing I'd consider that could overrule them.