I'm having the same issue as everyone above. I was wondering the same thing as the last post - the loan was an 18 month loan, not starting in summer 2022 but in Jan 2022, and maybe because Spurs have already reached the CL Group Stage there's no event happening in the game to trigger the clause becoming active. It should already be active as it was achieved when Spurs finished in the top 4 IRL in 21/22.
FWIW, I've also never read that the clause was dependent on CL qualification IRL. I think it's just a straight up optional future fee.