Have to agree with the other posts here, I wrote 'an hotel', generally considered correct in the UK as the H is almost silent, and was told I had made a typo. I assume this relates to the app being written for US English, not UK. An hotel should be marked correct with no typo.
I check the incubator and an hotel is there. Here are the top two sentences:
I do not want to sleep at a hotel.
I do not want to sleep at an hotel.
You likely had another error and it tried to match your wrong answer against the preferred answer, giving the typo message.