Maybe reading too much into it. One may certainly say "Je me suis absenté de mon bureau" to mean "I was away from my office" or "I was away from my desk". It could definitely include the idea of "...pendant deux minutes". It is not limited to, but may include, a day off, a vacation, or some other extended absence or simply going across the hall, on a coffee break or away at lunch.
"absentee" (feminine form) should also be accepted (assuming a female speaker), shouldn't it?
"Je me suis absentée de mon bureau" is accepted. Don't forget the accent--it's not optional.
In the recording the voice is female, so Je me suis absentee should be accepted
Duolingo doesn't work that way. The gender of the voice is not relevant to the words spoken. Duo started out with only the female voice and used that for several years. Now there is a male voice, too. But unfortunately, the sentences are not selected to be read by a specific voice. As to the audio exercise, "Je me suis absentée de mon bureau" is a homophone. I have added it to the list (for audio exercises) but it may take a while for staff to act on it. BTW, don't forget the accent on absentée -- it is not optional.
The Collins Robert dictionary I have gives s'absenter de meaning to leave (to absent oneself from) but 'I left my office' was rejected
I thought the sentence required an active sense, but "I went away from my office" was not accepted. So how should I translate "I went away from my office" -- if I ever needed to?