IOF tariff after restarting Inverter

I have a Giv HY-3.6 Gen.3 Inverter (along with 9.2kWh battery, and 12x PV panels). I’ve been on the Intelligent Octopus Flux tariff since October 2023. Few, minor problems but no real long-term issues. As an IOF user, I get Premium membership with Giv.
A couple of days ago, I was checking the Portal’s Inverter “Remote Control” page logs, and noticed that there had been no IOF comms for more than 12 hours. I also noticed that the “Your inverter is managed by a third-party. You can’t make any changes.” message had disappeared. No internet issues, so I restarted the Inverter.
Within 30 mins., or so, IOF messages started to trickle through. The system has worked fine ever since.
Anyone got any suggestions how I can return to being “locked-out”?! I don’t want to be held responsible for making changes to the system - am perfectly happy with Octopus having full & total control.
The Account Settings > Account Security page shows that the Octopus API key is still present & correct (of course). The only thing of note is that the key is dated 06Jun2026 - this must have been automagically updated when the Premium account was enabled.