It seems like some of the compatibility issues have been resolved, but not all of them.
One of the earlier exercises let me use template strings, and then I saw some comments that, for others, this had thrown an error.
However, just having completed exercise 8, it wouldn’t let me pass from Task 4 to 5 unless I used function declaration syntax instead of an arrow function i.e.
function displayStaffStatus() {
};
instead of
const displayStaffStatus = () => {
};
This is particularly confusing and inconsistent, because in a previous exercise it had let me use arrow function syntax for the displayFuelCapacity() function, which appears earlier in the same piece of code (in the same file)!
You are right that there are lots of bugs in this lesson: have you (or anyone else) reported this issue and some of the specific bugs via the designated Bug Report form?
For anyone who doesn’t know how to do this: from any lesson, click Get Help in the bottom right of screen, then select Bugs from the drop-down).
Here’s a link to instructions about how to do it:
https://help.codecademy.com/hc/en-us/articles/220711148-Report-a-Bug-or-Typo
Note: you must include the URL of the relevant exercise in the description field.
As someone who is currently working through this lesson, I do get the feeling that improvements are being made. However, it is definitely still a work-in-progress, so by submitting bug reports we’ll hopefully speed this up and make things less frustrating for those that follow! 
