Hi and welcome,
Sjogrens is one of the alternative dx for MS but i honestly don't know a lot about it other than there can be similarities symptom wise and the test evidence is considerably different....unlike other diseases that may produce Obands unique to the CSF for a period of time and then disappear, with MS once Obands show uniquely in the CSF the Obands are always present, Obands can increase over time but they don't disappear...
You said your "L.P. showed 3 unique CSF bands and 1 in serum (4 total)" the number of Obands you have are not calculated by adding them together, from my understanding if you have 3 CSF and 1 serum, the 1 in the serum that matches the 1 in the CSF wouldn't be counted and that would likely mean you have a total of 2 unique Obands.....matching Obands are not counted as being CSF Obands, Obands seen only in the blood and not in the CSF are also not counted, only the Obands that are seen in the CSF that DO NOT APPEAR IN THE BLOOD are counted for a dx of MS.
Depending on the type of lab testing that was done, some tests require 2+ unique CSF Obands to be outside the normal range and others require 4+ unique CSF Obands, so if your neurologist isn't seeing any diagnostic significance with your LP results it's highly likely your results are not in the abnormal rage to be diagnostically meaningful.
"5. Diagnostic of Neurological Involvement in pSS
5.1. Cerebrospinal Fluid
CSF may be useful to classify some manifestations. Lymphocytes may be found in some manifestations usually less of 50 cells/mm3. In aseptic meningoencephalitis, CSF is abnormal with a higher number of lymphocytes, increased level of proteins, and intrathecal synthesis of gamma globulins [75]. The IgG index is increased during periods of disease activity in up to 50% of cases. CSF is also necessary to the differential diagnosis (i.e., infection, multiple sclerosis).
Oligoclonal bands (specifically more than three bands) are highly specific of multiple sclerosis diagnosis. These bands have been reported in about 20 to 25% of pSS compared to more than 90% in MS patients [76–78]. The oligoclonal bands are not stable during the course of the pSS and can disappear after treatment with steroids."
https://www.hindawi.com/journals/ad/2012/645967/
You asked "...do bands = symptoms" and the short answer is no, the presence of Obands in the CSF basically only suggests inflammation of the central nervous system due to infection or disease.
I hope that helps......JJ