Did you install Sage using a package manager (Aptitude, Conda, ...)? Not sure how installing optional packages on top of such installations of SageMath work.
I would suggest building from source, with the extra benefit that you can get SageMath 8.7. Follow the instructions at http://doc.sagemath.org/html/en/installation/source.html -- You received this message because you are subscribed to the Google Groups "sage-support" group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-support+unsubscr...@googlegroups.com. To post to this group, send email to sage-support@googlegroups.com. Visit this group at https://groups.google.com/group/sage-support. For more options, visit https://groups.google.com/d/optout.