Ubuntu 19.10 some drm content not streaming

Not exactly an answer, but I can't post a comment...

I emailed ITV about this problem and received this reply:

Thank you for your email.

I'm afraid that Linux hasn't ever been fully supported on our website.

We are however looking into an issue where DRM content is causing a error message to appear on our website.

If you are getting a message to update your browser, this will probably be resolved for you once they have fixed the issue with DRM content.

If I can be of further assistance, please do get back in touch. 

So I guess we wait and see, but doesn't sound hopeful. It's not clear to me who "they" are (as in "...once they have fixed..."); ITV or browser authors? Nor if this is definitely related to the problem - I have not been prompted to update my browser.