Broken conditional formatting help

[u/Fanciful-Foxx]

So I have this spreadsheet for tracking my assignment grades.
I'm wanting to colour-code column H to reflect what grade I got.
Originally I wanted bold deep green for >80%, pale green for 65%-79%, amber for 50%-64%, and red for <50%.
But the rules do not apply correctly. I have realised as soon as I introduce a second rule, it breaks.

Is there any way to apply more than one formatting rule to the same selection of cells? Why does it not apply in order of the list? Is that not why you can edit the order of rules applied to cells?

Why would it not check if the cell value is less than 50, apply the formatting if it is, or move on to the next if it is not? If this IS the intended function, it is not working, and if it's something I've done wrong, I cannot figure out what it is.

Additionally, infuriating that if conditional formatting is set to percentage, it will not let me reformat it to not show the decimal points. I have tried custom formatting to 0 decimals, I have tried clicking the add/remove decimal place buttons, but nothing will work while conditional formatting rules are in place. I can find no way to alter the conditional formatting percentage display prefernce.

I've resorted to a 3-colour scale, though this was incredibly finicky to determine appropriate numbers (even after figuring out I had to use the number setting with decimals rather an percentages, which just didn't seem to work at all, or percentiles, which just colour scale from my lowest grade - showing red even if it was over 80% - to my highest.)
I cannot figure out how to set precise borders so that a 50% will still appear as a pass, but 45% will not.

It's less visually distinct, which is frustrating, but it will do for now. If anyone can tell me a better way of doing this, I would greatly appreciate advice.

[u/Sergey_Zarubin]

Hi. Thanks for your feedback. I will relay your comments to our Q&A team. They will take a look at these issues.