Hi Laurent,
Thank you for your patience, and especially for digging into this and sharing the exact fix — that's very helpful.
You're right: in Joomla 5.4.7, the blog options (post format, video URL, etc.) are now stored in attribs rather than being pulled through the params object the way older Joomla versions handled it. Our override files in Helix3 3.1.3 weren't updated to reflect that change, which is why the video post format broke after the Joomla update. This was missed in our testing because our test environment wasn't yet running 5.4.7 at the time of release — that's on us, and we're updating our QA checklist to test against the latest Joomla point releases going forward.
I've passed your fix to our development team to verify and apply the same attribs-based approach across the other post formats (not just video) so this doesn't resurface elsewhere. We'll include this fix in the next Helix3 patch release, and I'll update this ticket as soon as it's confirmed and scheduled.
In the meantime, since you've already applied the fix locally, feel free to keep that in place — we'll make sure the official update doesn't conflict with it.
Thanks again for your patience and for taking the time to report the exact cause.
Best regards,