Clip Jumps from 23 miliseconds to full second on timeline

When navigating on a clip on my timeline, it always jumps from 23 millisecond to the next full second. If I try to cut a clip exactly at 4:45 (4 seconds and 45 milliseconds) I'm not able to because I'm not able to navigate between those 23 and 59 milliseconds.

Here is a gif to illustrate since it's kind of hard to explain with words (sorry for the cellphone recorded quality)


Can anybody help me understand what's happening here and why can't I navigate without this weird jump?

Thanks!

[Peter Chamberlain]

It’s a frame count, not milliseconds and so in a 24fps timeline this is correct.