Mouse ignores certain parts

As the title says, Roblox Studio makes my mouse completely ignore certain parts.

Let me explain: I’m trying to make a system, where if you hover over a certain part, a gui pops up.
Now, this has nothing to do with the script, because it says i’m hitting the part under it, so it just goes through it.

Note: Clickdetectors also don’t work.

What could the issue be? Thanks.

Could you please send the properties of the parts you are trying?

Just a normal part with a clickdetector, nothing special.