Harry Kane's transfer is indeed the most complicated compared to the others because Spurs are sometimes very annoying for clubs who want to buy their players or even the players themselves are also annoyed with Spurs' policy of selling their players. Therefore I think Harry Kane's transfer to Real Madrid is unlikely to be successful as long as Spurs still want a high fee.
Apart from that, the news about Mbappe is still quite hot until now and Real Madrid doesn't seem to want to push too hard to get Mbappe because they also don't want to be in a hurry. I think Real Madrid will start negotiating with Mbappe again when his contract is finished with PSG and for now there will probably only be rumors without any endless clarity.
Tottenham chairman Daniel Levy simply doesn't want to sell Kane to any team for an unsatisfying amount of money. Because he is really their everything now. I have no idea where they could have finished this season if it weren't for Kane's huge contribution with 30 goals. He is about to become 30 years old next month which is another important information. Because spending like 120 million euros or up for Kane from now on wouldn't seem very logical for the majority of rich teams.
Real Madrid must be finding more logical to wait for Mbappe to use significant amount of their funds. Or they would sign a more sensible-priced skilled striker this summer most probably.