If the migrant comes from an affluent country and can offer to pay an upfront rent, say 4-6 months, I will choose this tenant.
That is a good point. If the tenant is willing to pay the term of the lease in full upfront, the risk is reduced to you.
However, I agree with the others that your PM is not undertaking their legal requirement.
They are in breach of their ethical standards and I would have served them notice to terminate the agreement imeediately followed by a quick kick up the bum to the licensee of the practise.
I cannot understand why landlords are so frightened speaking out against bad service and why they just accept it and whine on sites like this.
You are not making money out of an asset that was purchased to do so.
The person you have contracted to undertake a service is not doing it correctly.
What is so hard about changing something that is not working?
If you cannot stand up for yourself, find a friend or mentor to assist.