It's totally common for any person to freeze up in situations like that, even when everyone involved is speaking the same language. Those situations just happen really fast.

(1) "Are you missing anything?" Is the very base question to suggest that they check if something's been stolen, or ask if they have had something stolen. Shows concern and care with not really any possible misunderstandings.

Are you two...
Are either of you... Both address the group

(2) "Are you missing something?" is a more detailed sentence. It'll very very likely be interpreted exactly like (1), if the speaker and listeners are 'on the same page', or at least know all the details and context for the question. However, particularly between native speakers,
(Shortened to "Missing something?" at times ) This shortened form accentuates the potential implication of using "something" instead of "anything", which is that the sentence has a different tone than (1). Instead of concern for the listeners' possessions, it can show sarcasm (and by extension humorous or mocking tone). It's what someone might say when a person makes a dumb mistake by leaving an important object behind, and the speaker is cheekily telling them that they obviously left something behind. This is largely a movie/tv trope and probably isnt something you should worry about.

Saying "Do you miss anything" makes the word "miss" slide out of meaning "lose an object", and into "not notice an object". Strangely, the -ing ending is crucial for the first meaning (English!!! WHY!?)

Other than using the word "missing"... You could say "(Has) anything been stolen (from you)?", I guess, but using the word "missing" is the best way.

By the way, before this I'd never seen the abbreviation ca. before, so kudos on that lol