We did not really find a definive solution for the detaching of text-styles issue – and we used the same remedy as you described and reset text-styles manually.
But, what we found out is, that overriding the styling of multiple variants in a variant set at the same time sometimes causes the text styles to be detached, especially when you have components with nested components.
Also, styling the actual variant set container (we often do dotted borders and background colouring) caused text styles of the variants placed within to be detached.
I am not sure if the Figma team made some changes that better the behaviour in the last months, but paying close attention to text-styles when setting up or re-styling variant sets helped us to work around the issue for now.
Same thing here. What I was able to identify is that when I manually change position of my text object, the text style get instantly detached. I made a video about it.
I just experienced this unprecedented issue after publishing variants to my team library. The text styles were attached when I published them 2 days ago. But today I noticed that the text layers in the base components have the styles attached, while the parent components have text layers with detached styles, not to mention they’ve all gone up in weight. All the text layers were affected! This is bad since there are so many people on my team using our library. No one should have to go back and reattach multiple styles. See screencap below.
fix this please x2, it’s a awful experience
See screencap below.