Meta E4/E5 Phone Screen Reject

YOE: 5
TC: 50 LPA
Current firm: HFT firm

I don't understand why it happened.
I have been preparing pretty much all the time since the last 3-4 months. Have solved around 600 questions on LC.

The questions were pretty simple:

Write a method that determines if a string is a palindrome or not (ignore all characters in the string except lowercase and uppercase english characters) - I wrote a two pointer solution to this and created a set of valid characters to check. At one place, I used an if instead of an elif (in Python) which the interviewer pointed out which I fixed.
Given an array of integers (both positive and negative), determine if there is a local minima in the array. ( a local minima is defined as an element a[j] such that a[j-1]>=a[j]<=a[j+]. Only compare the right element if the index is 0 and left element if the index is n-1). - I gave a solution in O(n) but the interviewer pushed me to solve it in log(N) using binary search. He had to hint me a couple of times but I was able to come up with the BS condition and explain to him how it worked.

I completed both of them under time and had 2-3 minutes for normal questions.

2 days later - the recruiter told me they are not progressing with my application.

I am currently working in a HFT firm (have around 5 years of experience), which I don't like due to politics and career stagnation. I am not sure what I did wrong here. What is Meta's criteria for a successful solve? Shouldn't they assess me further on more rounds to decide overall how I performed?

Quite confused and frustrated as well.