An application used a combination of @Picklist and @dblookup. The user interface worked well, but the underlying form failed.

While in the form, another configuration document was created in another window, the picklist found it, but the @Dblookup failed.

The reason was that @picklist uses "NoCache" by default, and "NoCache" was not used in the @Dblookup field and this was causing the problem, so use "NoCache" when using @Dblookups in conjunction with data that was obtained with @picklist.