Also been reporting online for over a year with no rejections and then last month, a rejection.
The rejection reason indicated that we were on a tourist visa within their system. Went into the immigration office and it looked liked they called the central office and explained that our visa is not a tourist visa. Processed the 90 day report in the immigration office.
I came away with the feeling that our rejection was to get us in to do another in-person 90 day check in to confirm our address again.
I converted from an OA visa to an OX visa partway through my OA visa.
The process I took was cancelling the existing insurance and starting a new full insurance from the intended start date of the OX visa.
I went with the same insurance company because they had my details and it was a no hassle's process.
Going through immigration, the visa stamp was to the end of our passport expiry date which was 3
***
years even though our insurance was only for 12 months. I haven't reached the end of the first 12 months of the OX visa, so I'm not sure of what process they will follow in confirming continuation of health insurance.