Ubuntu has recently updated their ca-certificates package and blacklisted TrustCor. The relevant Ubuntu bug is at https://bugs.launchpad.net/ubuntu/+source/ca-certificates/+bug/1998785 and they reference https://hg.mozilla.org/projects/nss/rev/a871902c05907db3150ac8b7f6a80dd01b5d38c9 as an upstream commit.
