Vimeo Security Problems

I have a new MacBook Air with up to date operating systems. I have Safari and Outlook as browser options. I am a quilter and have purchased 3 different courses about my craft, all of which are on the Vimeo platform. I am now frequently getting error messages about security concerns and therefore the videos won't load. Randomly, the videos will load, and from what Ive read, its because Vimeos security risks are fluid, shifting from secure to insecure frequently.

Ive never had this problem before. Is it a MAC issue?