See Audacity. Open source but the name is registered trademark and owned by the Muse Group
https://www.audacityteam.org/copyright/
https://github.com/audacity/audacity
Or Blender also another open source project but registered trademark
https://www.blender.org/about/logo/
Krita too
https://krita.org/en/item/krita-trademark-policy/
https://invent.kde.org/graphics/krita
There are countless examples
It's now administered by the Linux Mark Institute.
And there are handful of OSes registered as UNIX Certified https://www.opengroup.org/openbrand/register/
Yet there is no single "UNIX OS"
So it's now a bit more like x86 (family of similar products that work somewhat similarly, though x86 doesn't need a license any more) rather than Pentium (a product or range from a specific company).
Kurento the project is Apache-2 open-source, you'll find all its source code here: https://github.com/Kurento/kurento
its website was kurento .org but the trademark of the name (and the domain) is owned by Twilio, who recently had the gesture of redirecting all accesses from this domain to their own, without prior warning. No replies to emails, or reasons stated. Not that they needed one though, as they are indeed the owners and can do whatever they want. Just a nice "contribution" they made to OSS, it seems.
I mean, that's not exactly great either if true, but I think it's just as much a possibility as this being intentional.
Note that I've had to run around helping projects deal with both that sort of situation and the sort where the company was deliberately screwing over the project out of active malice (take a bow, Nagios Enterprises) and this definitely smells like the former based on what little information I have.
But being on the receiving end of such an event tends to suck baseballs through a carbon nanotube straw either way, and believe me that you have all of my sympathy and my nerding out trying to analyse how said event came to pass was, just, well, just as much a result of having waded through similar swamps previously myself as the sympathy :)