Hey Kevin, thanks for being in touch and apologies for this. What version are you using - may it be 1.17.0? We had a bug in the beta version for a short time that prevented users from closing the node details view. Updating to 1.17.1 should fix this.
Thanks! I could indeed fix by restarting the instance with the following advice from email Support:
In short you’d have to head over to n8n.cloud, change any of the settings, then hit Save changes for n8n to restart and fetch the latest ai-beta image. After the restart, you should again be able to close the node details screen.
Hope that can help if others are in this situation!