I'm willing to travel to Miami once or twice a year and manage the properties from Spain, hiring a good property manager to address issues, find new tenants, manage payments, and clean the property for new tenants.

It is a recurring issue that will come up whenever new tenants move in or out.

Dealing with frequent lock issues can be a real hassle, especially with multiple units.

Also, you are offering way too much, not sold for a year, ok it has issues. 

Actually he brought the issue to your attention, was absolutely correct and the best thing you can do is make a note of it for the future. 

I am looking at some mobile home parks in my area I would like to puchase.

Sounds like a hard money lender that wants to take a property from you when you default.There's a lot of issues here starting with a guy that will loan you money and once it gets difficult wants you to abandon ship- red flag.There are a lot of unknowns here but trying to dump it seems like a 100% guarantee to lose money.

Somehow, it seemed to blow up as an issue during Covid. 

. - Rehab financing is less of an issue than take-out (permanent) financing here.

Zero-Issues.