There's a guy on YT by the name Louis Rossmann. He owns an electronics repair company. He did a video on fuses on YT. He bought a bunch of different brands off amazon and tested them for amperage compared to their listing. The results were all over the map. Some way higher than where they should have blown. It was an eye opener.
I only wish he did a control test on some local auto shop Bussmann fuses to compare.
Not saying that's it, but it may explain why the terminal melted and the fuse didn't pop. That's scary.
Hutch