Landlords, what are you looking for in a tenant when you get multiple applications for your property?

I've been trying to find a house to rent (south Wales) and I'm at my wits end, landlords always seem to be going for other applicants and I just don't understand why. I'm a working professional, full time permanent, I work in management in healhtcare and have enhanced DBS check, £50k income, applying for properties well within my affordability range, no pets, no children, good credit score, no CCJs etc, EU settled status, character references from doctors I work with, I've been in my current place for 3.5yrs with no issues....i just don't know what to do anymore, in a week I'll be homeless and will have to move in with a family member. Is it because I'm single? Settled status and not British? Anything I can do to reassure the landlord I'm a good tenant and increase my chances?