It's a good idea to read the prospectus/disclosure before you...

It's a good idea to read the prospectus/disclosure before you buy for anything other than a fully paid ordinary. It could be worse... you might have bought a part-paid security with a call due soon.

You'll find the document here: https://www.usmastersresidential.com.au/investor-centre/key-documents/

My key takeaways for the CPUs are:

1. The payment is a dividend, not an interest payment like a bond. As such it is not guaranteed. If the fund doesn't have the cash to fully pay the dividend it doesn't have to. The only significant of the "preference" units is that they get first claim on the available cash. The the CPUs don't get their full dividend then the ordinary units get nothing.
2. Under normal conditions the CPUs can't be converted by the fund into ordinary units until 1-Jan-2023, and then only at the start of a payment period: 1-Jan or 1-Jul in any year.
3. From 1-Jan-2023 the CPU payment goes from $6.25 to $8.75 per annum, unless the fund decides to convert the units at that time.
4. As I read it the fund is only allowed to convert the CPUs into ordinaries, there is no option to redeem them for cash or buy them on market.
5. I would expect the fund to convert all the CPUs at the earliest opportunity as this requires no cash and relieves the fund of a substantial cash commitment. So I expect there to be six more dividend payments before conversion.
6. I would also expect there to be a massive dump of CPUs on the market in the lead-up to 1-Jan-2023, and a massive dump of ordinaries afterwards, so it will could be difficult to retrieve your capital around that time.

But read the document for yourself and form your own views. There's a decent summary of the conditions in the early pages.