I am almost the opposite- I crack under pressure. I run better when it’s a meet that “doesn’t matter” or in a situation where I am much more relaxed.
For example-when the fastest runner scratched in my 400 at my conference meet last year, I was relieved because I knew I was the fastest runner. I ran a 49.9 a .5 second PR at the time.
The next week I was the 3rd seed in my sectionals, top two go to state meet unless I hit 49.9 again. I put myself under so much pressure. Ended up running a 51.6, my slowest 400 time ever besides my first ever 400 race.