I believe it’s 3 months - although I can’t be entirely sure. The main thing is to not get three or more 3* or less reviews in that period once you have a warning - you will be shut down for a month, then your listing removed.
It's been a while since you posted and I'm wondering whether you managed to get a resolution to your question? @Pete28 has left a comment below for you too.
It'd be great to hear from you, so we can understand what the resolution was but also to support other Hosts who may have similar questions in the future. 😊