Increasingly, browsers are blocking third-party cookies, which prevents the normal LTI 1.3 login flow. IMS/1EdTech has an alternative login flow that most LMSs support but it appears that Moodle does not yet support. We can work around this by advising that instructors set an LTI 1.3 tool to always open in a new window, but unfortunately the deep-linking workflow in Moodle seems to require that the tool be able to be opened in a frame, which fails when the user's browser has third-party cookies blocked.