Hint #1 is very good.

I would have deleted the first hint because it is not a hint at all. Can be easily misunderstood.
Hint #2 is normal.

I can't figure out how hint #1 relates to the solution.

A beautiful problem. I liked it very much. Thanks.

this is not the shortest way?? i got the 3.95 noticing that bugs cant fly... cant proceed any further.

Which diagonal has length of 3.74? Can a bug walk along it (i.e. does it stay on a wall all the time)?

Sorry, but I just didn't get an explanation to that.

Is your question exactly the same as the one below?

We find a large diagonal of a right triangle, according to the Pythagorean theorem. In 1 test I got the answer 3.74, but in the author the answer was 4.24. Why?

Because the bug can't fly.

Note: The bug cannot fly and has to maintain contact with a surface at all times but can walk up walls.

Can't understand the idea of kata, why we can't go through the diagonals. It is the shortest way. In first test I got 3.74

I translated this to Rust, please take a look!

Julia translation

It's not the only possible path.