@TheBiter Thanks for the detailed writeup. I just discovered that I overlooked that the test Timeline which I inspected had more animation clips following hidden to the right of the window (requiring scrolling), while I thought it had been the last clip already. My bad.
We have created an issue ticket here for this issue:
EsotericSoftware/spine-runtimes2318
We will get back to you here on the forum as soon as we have a fix to offer.
Thanks for reporting!