What is going on with gpt 5.1 lately?

Hi everyone,
Something strange is going on with gpt 5.1 for me. Ever since it came out, it started writing in a really weird way. It turns numbers into letters, makes everything lowercase, the layout looks messy, and it keeps writing things like a rough draft instead of a clean answer. I tried updating my memory instructions but nothing changed. Is anyone else dealing with this since 5.1 came out, and does anyone know how to fix it?