Sorry for the very late response; I stepped away from the forum for a while.
I am still using Tickmill without issues. I did try Oanda for a while because they offered an account in CAD, which Tickmill does not. However, I couldn’t get past how much bigger the spreads were, and I came back to Tickmill.
I don’t know why the IB link didn’t work, but at this stage I don’t even know what my IB log-in details are, so unfortunately I’m not in a position to try again. I think that it is a shame that Tickmill has a programme like this but makes it so difficult to implement.