I am trying to finalise my payment for the DRUID conference and noticed that the fees increased today.

The website says "Sponsorships from the partner universities have enabled an early-bird conference fee (applicable until September 1, 2021) of 510 EUR. After September 1, 2021, the latecomer conference fee will be 615 EUR.” I assumed that the 1st of September is included but it does not seem to be when I try to register. Can you please have a look at this. Does this mean that authors with accepted papers can no longer register?