I'm testing our upgrade to Moodle 3.9, specifically the integrated H5P/Content bank.
I'm getting an error when I try to add images to a newly-created H5P activity in the content bank - Invalid Security Token
I can add the same images elsewhere in the course in Moodle 3.9 (e.g. in a Moodle Book or via ATTO), and I can add images in an H5P created in our older plugin for Interactive Content - the error is with H5P in the content bank, in all browsers, and for all H5P activities that can use an image.
Any ideas, Moodle community?!