I'm a user like you, I don't think TMDb can answer. the problem is probably from Letterboxd side or maybe both side, usually updates take about 24hours.

Now I'm searching the web because all my editing since 16 July are not updating on Letterboxd, was wondering if I was the only one.

I will try to report the problem to Letterboxd

In meantime I have done that to help you a little:

Import shortcut
To import brand-new additions to TMDB immediately into Letterboxd, enter a URL in the following format (with the new ID) into your browser:

https://letterboxd.com/tmdb/1515032

https://letterboxd.com/film/hills-dont-dance-alone/

Hey,

Thank you for your answer. I have tried doing this, but this has brought only partial information to Letterboxd and isn't getting updated now.

If there is something else, I'd love any help.

Yes, this method, bring only those informations that's it, just the name of the movie pretty much. For the rest we have to wait Letterboxd daily update. But there's seems to be a bug now... Well I guess there's a bug. I don't know for sure.

hey im also having the same problem too! Half of my crew is missing on my film on letterboxd. Let me know if you find a solution!