Web browser timing out with Lovelace

Hi folks,
I don’t think this question is in another post, if it is apologies.
My environment:
Home Assistant Supervised - core-2021.3.3
Running on Debian (4.19.0-14-amd64) in docker.
My problem:
Any web client connecting to my HA instance (locally via IP address) times-out after a little while, that is elements of the lovelace pages fail to refresh / respond.
If I invoke control+shift+r, it never refreshes. I get a spinning wheel in Chrome (along with Edge, Mozilla, etc). This happens on multiple machines.

Strangely there’s one page in particular (aarlo_glance) that doesn’t ever load, the rest do the first time, then they fails to refresh.

I’ve got a request in with twrecked here: https://github.com/twrecked/hass-aarlo/issues/413. He’s been awesome but can’t see any errors in his glance_cards. I suspect HA is bombing out before it renders the aarlo camera feeds.

Mobile client (iOS) works perfectly…

It’s odd and terribly frustrating.

Any clues where I could start to investigate?
My understanding of pyhton is weak. I can see in my debug logs there are some tracebacks, but don’t know how to decipher.

I ended up creating a new dashboard, copying the glance cards to the new dashboard.
And would you believe it works a treat!
Commented out the page with the offending glance card on the original dashboard, it’s now behaving as I would have expected!

Can’t explain why it played up, but creating a new dashbard seems to be a work around.

Thanks to anyone that have pondered over my problem.

This can be deleted/resolved I guess.

Cheers,