I asked mistral/brave AI and got this response:

How Many Rs in Strawberry

The word "strawberry" contains three "r"s. This simple question has highlighted a limitation in large language models (LLMs), such as GPT-4 and Claude, which often incorrectly count the number of "r"s as two. The error stems from the way these models process text through a process called tokenization, where text is broken down into smaller units called tokens. These tokens do not always correspond directly to individual letters, leading to errors in counting specific letters within words.

I mean, that's how I would think about it...

Skill issue

The terrifying thing is everyone criticising the LLM as being poor, however it excelled at the task.

The question asked was how many R in strawbery and it answered. 2.

It also detected the typo and offered the correct spelling.

What’s the issue I’m missing?

From a linguistic perspective, this is why I am impressed by (or at least, astonished by) LLMs!