dKatsuro

I'm having this issue as well and despite Security Defaults already being off for my tenant (and has been, no changes in a long time) AAD's Sign-Ins activity log shows...

Unfortunately I have enabled MFA and used App Password but it still fails to work for me.

Are you casting images? I know there is a hard limit on all versions of chromecast (Ultra too) that limit image casting to 720p. Other thing you might want to...