Recently, I had multiple days in a row of bad physical luck. It coincided with Katrina's first visit to my new town, so I got a reading. I wore what she tell me to wear, I put green stuff in the south section of my home, I made sure I was wearing season-appropriate attire. Nothing. For three days I tripped, and I found nothing online that gave me any idea why.

Has this happened to anyone else? Was there a cause or was it just three weird days of my town generating bad physical luck for me no matter what I did?

Was the item a theme of clothing, glasses or tops?
One time I had a theme top and put on a tank top and she said that I wasn't wearing the right thing.
I had another player with the same birthday and sent her up with a shirt in the theme and she passed.

Another time I wore a tank top when it was a theme top and it was okay.  Not sure what happened.
Do you have a lovely phone in your house so you can check what clothing you need to wear the next day?  Each day it changes.  There is very good guide on gamefaqs done by Liquefy.
It tells you counts for Vertical, Horiztonal, animal print and other things.

The animal print dress was the one that caused me a lot of problems.  Looked up his list and the cat and fluffy dress count as animal print.  It doesn't have animal print on it but it's a cat dress.

The cami plaid dress is the only dress that will count for a plaid dress.

I have extra towns and one of them is ahead of my main town.  I gave all the mayors the same birthday.
Started writing down the lucky item of the day from the town that is ahead.  I just check the list now and put the item on when I play my main town.

All she told me was "Caps". I tried multiple caps, nothing worked. Changed my outfit a few times. Still bad. It's all sorted now, it was just really strange. And no, I don't have the lovely phone yet. But thank you for the tip!

Did you talk to Katrina afterwards? She can give you a good luck charm for 10,000 bells.

Your luck changes every day, so what you need to wear [if you have bad luck] will depend on the day ...

The lovely phone said to wear a knitted cap.  I put on the Striped Knitted Cap and it didn't work.
I was tripping.  Put on the Pink knitted hat and I stopped tripping.
It wasn't a cap but Katrina was happy.   There are a few items that are hard to figure out.