"Synovy otázky nechápeme."

Translation: We do not understand our son's questions.

[Praha2017]

"We don't understand my son's questions." is missing as an accepted translation, as the alternatives 'my' and 'our' are both accepted in many other sentences.

[nueby]

Not everything is acceptable everywhere because the rest of the sentence matters. In this sentence, why is the speaker including someone else in the "we" but not in the "my"? I expect the scenarios you come up with to need the possessive pronoun even in Czech. I did provisionally add the alternatives with "my".