The request limit

I’m sending 4 requests every 10 minutes and keep receiving 429 Too Many Requests error. What’s the request limit exactly?

This is what I found in the documentation:

Our REST API has a specific rate limit of 50 requests per second (by addon on one workspace) when accessed using X-Addon-Token. Exceeding this limit will result in an error message with the description “Too many requests”.

According to this, I shouldn’t be anywhere near the limit. Can someone explain why I’m getting the 429 error then?

It turned out I made more requests that I thought, but after reducing the number of requests to 5 per second maximum, I still get the 429 error.

For the record I’m using X-Api-Key, not X-Addon-Token. Is there a different rate limit in that case?