The previous owner never enforced the late fees, although one of the tenants was chronically late (undisclosed at time of sale),I sent all the tenants a change of ownership letter restating the terms of their lease, including the late rent penalties.  

Fortunately I am alive, but with chronic pain in my lower back, as I have herniated disks/bulging disks/protruding disks, disc degenerative disease and an annular tear.

You might discover from court records that their problems didn't start with massive thoughtless spending, they started with sky-high medical bills for a chronic illness a few years ago.

I have a chronic illness and have already met my maximum out of pocket maximum for 2019!

I am a chronic over-sharer.

Even low levels of ozone exposure can cause the following conditions: coughing, chest pain, shortness of breath, wheezing, and throat irritation;worsened chronic respiratory diseases, such as asthma;increased risk of developing bronchitis or pneumonia; andcompromised ability of the body to fight respiratory infections.People's susceptibility to ozone varies widely.

The other thing is, the Houston Chronical had posted an article saying buyers to beware of the "30 day wait period" when getting flood insurance.

I was wondering how people have dealt with tenants who chronically pay rent late.

Whether they were complainers, chronically late, had little regard for common areas or people's space, required additional assistance, rule violations, neglect maintenance issues etc.

Seems like it's a chronic problem and if the current owner can't deal with it, go to the applicable city or building department about the hazardous and dangerous and unsanitary conditions the house is in.