Stuffed Cherry pepper problem

I made a batch of stuffed cherry peppers stored in EVO, Now after just a few days I go to try one and they are all over ripe mush like. What did I do wrong.
I got them nice and firm, washed and cored and stuffed.
What could cause them to lose there crunch?

Putting things in oil, unless you store them in the fridge, can risk botulism. Oil is a warm environment that lacks oxygen, perfect conditions for botulism. I would not risk it.

It would be safer to use a well tested recipe to pickle them in vinegar and salt brine. I would throw them away to be safe and start over with a well tested pickling recipe.

Stuffed Cherry Peppers

1 lb prosciutto (1 lb sliced is ~37 slices)
1/2 lb provolone cheese (sliced ~ 1/2" thick)
2 lbs cherry peppers (~ 2 pt or 50 peppers)
1/2 gallon white vinegar
1 quart extra virgin olive oil
1 quart canola oil
1 small onion, thinly sliced
bay leaf
dill weed
chopped garlic
Parmesan cheese

Wash cherry peppers and place whole, stems intact, in 1 gallon jar.
Fill jar with white vinegar.
Let stand at least one week or up to 3 weeks.
You may need to add more vinegar to keep the jar full as the peppers soak it in.
The peppers will float, make sure to keep them covered.
After soaking for at least a week, pour out vinegar and rinse peppers in cool water.
Remove stems and seeds.
Expect to lose 3 or 4 peppers during soaking.
Cut provolone to the appropriate size to fill the peppers.
Cut the prosciutto slices in half.
Wrap the provolone with a 1/2 slice of prosciutto (or 2 for larger peppers) and stuff into pepper.
Add some Olive Oil to the jar.
Add Onion, Rosemary, 2 or 3 Bay Leaves, Dill Weed, Basil and chopped Garlic to oil.
Place the peppers in the jar and fill the jar with 50% Olive Oil and 50% Canola Oil.
Top off the jar with a sprinkle coating of Parmesan cheese.
Let soak a minimum of one week at room temperature.
You may want to refrigerate for longer shelf life.