@etherealcataclysms - If your stylomandibular ligament is calcified, I would expect it to show up to at least some degree, but it might also depend on the scan angle as to what’s visible & what’s not.
Also, I notice that your cervical vertebra have a slight kyphotic curve which is the reverse of what it should have. You might want to try some gentle neck extensor exercises to start getting your lordotic curve back. That could help reduce some symptoms & might help stop or reduce the amount the lump pops out.
This link contains some exercises that can help with that: