Grafana in iFrame works on mobile, not PC

I’ve set up a Grafana dashboard view in an iFrame and it works fine when navigating to it with Chrome on my phone, but I get the error “…might be temporarily down or moved to another address” when viewing in Chrome on my PC. I’ve perused various forum posts and nothing seems to match this specific idiosyncrasy.

HA = using SSL
Grafana config:

plugins: []
    value: 'true'
ssl: true
certfile: fullchain.pem
keyfile: privkey.pem
allow_embedding: true
cookie_samesite: none

Any ideas why it would be working on mobile Chrome but not desktop Chrome?