by probing where the fuse was I mean, the fuse has probing points on the outside (mostly to test whether is good or bad without having to remove it). If you would have heard me when I measured you would have laughed...cause it was utter surprise.
Were you measuring across the fuse as in the photo below? If the fuse was not blown at that time, the cube was running, then I would suspect the digital multimeter auto-ranged to mili-volts. 50mv-60mv or 100mv would not be unreasonable.I just measured mine and found 20mv, I found a spec on these kinds of fuses that indicate 60mv for 30a is to be expected Even at 100mv at 30a the heat generated would be 3w, that is enough to make it feel warm to hot. In my case it would be 20mv at 30a: 0.6w and the heat seems higher than that.
The outside event is the connector, it's contract resistance with the fuse and how well it is soldered to the circuit board. One good way to check this is to measure the voltage drop on the fuse and the voltage drop measured on the circuit board (yeah, running the Cube out of the enclosure). Any substantial discrepancy would point to a poor fuse connector connection.
For some good background information on fuses and wire sizing see: Littlefuse
For information specifically on Cure ATC Blade Fuses see: Bussmann
Suggestion: If you have a question about the fuse replace it with a good brand automotive fuse. Littlefuse and Bussmann are long established top end fuses.