Maybe but could only have been on the mouse since the keyboard was working via the hub and I plugged and unplugged it a few times.
Are there any Windows diagnostic tools that might tell me what's going on here?
Device Manager, USB and find each HUB. In properties for each hub is a power tab showing available and in use power over the bus. Should show how much the mouse is asking for and receiving, even in an underpowered situation.
I'll have a look at that. There's that devices by connection option which probably makes it quite clear.
I did use it all day yesterday and unplugged it a few times. Every time I plugged it in, it worked fine. So beats me what I did wrong initially. The mouse still doesn't work when plugged in to the keyboard though but that's fine.