You don't use activations by reinstalling on the same computer, and you can even deactivate on a computer and thus free an activation.
You can try to reinstall Pigments, and you can try to update your graphic driver. But as it's a random behavior, then i don't know, if that will help.
If it's not happening in the standalone version, then it perhaps an issue that include your DAW, or if you have multiple pigments plugins in the same folder or similar that can cause a conflict.
If anyone else exsperience this issue, then it would be good to hear about it.