Hi @hanneke-de-graaf, thanks for your detailed description of the issue!
False-positives can sometimes occur with some actions that other plugins attempt, so you may be able to allow all future occurrences of this issue by clicking the “ADD PARAM TO FIREWALL ALLOWLIST” button on the blocked action itself. This might be enough on its own.
Sometimes, you might need to enable Learning Mode for a short time if further actions also need to be allowed for customers in lower user roles (or who can check out as a guest). You can read more about both methods I’ve mentioned here: https://www.wordfence.com/help/firewall/learning-mode/
Many thanks,
Peter.
