what do landlords and letting agents want to see?

[Mumsfan]

I didnt know renting a property could be so frustrating! please give me your insights.
my priority just now is finding a nice property to rent out for my daughter and l. She is currently in Hong Kong.
l had actually applied for a flat in Edinburgh and was accepted immediately by the landlord. Homeslet checks were all passed. l had sent my Nationwide bank statement showing >£60K, my title deed for an Edinburgh flat, purchased at £323K and TSB bank statement showing regular monthly payments by my current property manager, showing >£36K rental income.
However the landlord rejects my application 'as circumstances has changed' according to the property agent. l am “self employed/investor/landlord” l reckon its because l am considered unemployed / no tax returns / provided no references (could provide my current property manager, as an income reference). should l put all 3, “self employed/investor/landlord”? what would the property agent or landlord prefer to see? How about my current address? Hong Kong or my Edinburgh address? l am currently in Hong Kong, but live in Edinburgh with my relatives and will shortly be back. so can put either address. Edinburgh seems most suitable.

so frustrating, albeit first application, please let me know asap as there is another property that l like and like to apply for. The last option l have is handing a 28 day NTQ to the current tenants. But this is highly undesirable. opinions ?

perhaps renting from a private landlord, bypassing the 'safety net' of property manager?

I don't understand how you can have £36k income a year from renting out property and don't fill in a tax return. Which country are you a tax resident in Scotland or Hong Kong? Do you have a British passport?
Do you have a UK credit history e.g. bank account / credit card?
The rules for renting are different in Scotland to England and Wales.
You could ask one of your relatives who lives locally to act as a guarantor?
If your daughter is an adult the property agency would want her to sign the tenancy agreement as well.

PS according to HMRC rules income from property as a landlord isn't self-employed so it would be correct to put landlord/investor on the forms. You have to be registered as self-employed with HMRC to put this down and have another source of self-employed income.

catsndogslife, thanks for reply, l will put down landlord / investor instead.
my current property manager said other property managers would not require a tax return for a more favourable case, proof of sufficient funds and ability to pay, even offering to pay months in advance, maximum 6months would be a plus and might sway it in our favour with the landlord they said.