HotDoc can't be trusted. It's behaviour is inconsistent

[soswow]

I Am not sure what's exactly going on here. But here is what I see:
When your API is called I get 2021-09-30T16:35:00+10:00, I go to hotdoc and see:

But when I click through to see actual booking I get:

Relevant pieace of info. In some minutes latest date started to be reported 2021-10-28T15:35:00+11:00 and all hotdoc UI have showed things accrodingly.
Maybe there is some caching and appointment at 09-30 was snatched away very fast?
I don't think