Thanks so much for the video. That really helped in clearing up the problem. I found the same bands and imported them to try to provide a more clear explanation and show you how to separate a single band.
In your example, you try to separate 3/5 bands into separate products. The way the system works, you did actually separate them but it was into another group. I know the variants tab still has the (5) beside it, but if you look in there, you now have 1 product that includes the 3 colours and then another product that includes the other 2 colours you didn't want. That is why there is two products only, one is actually 3/5 colours and the other is the 2/5 colours!
To separate a single band, there is two ways to do so. First, in your video when you are selecting the colours you want separated, do it one-by-one and you'll see it making a separate product, rather than grouping the 3 you originally selected.
Or, when pressing the split option, select split by option which will allow you to split every single one into a separate product.
So, it's either one-by-one or all five split into separate products. I can see the confusion and it certainly took me a second to see what was going on at first. I'll be passing the feedback along as I think others could benefit from selecting three to split off individually. However at this time, this is the two ways to do so.
A final note, once you split the product there will still be a (5) beside the variant tab. That just means there are four other options. If you click it however, you'll notice only one product is actually active. Hope that clears it up. Let me know if you have any other troubles or questions!